BIOSITE DIAGNOSTICS INC
10-K, 1999-03-31
IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES
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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 10-K

                                -----------------
(Mark One)

[X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
    OF 1934

For the fiscal year ended December 31, 1998

                                       OR

[ ] TRANSITIONAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
    EXCHANGE ACT OF 1934

                        Commission File Number 000-21873

                        BIOSITE DIAGNOSTICS INCORPORATED
             (Exact name of registrant as specified in its charter)

                                -----------------

                      Delaware                          33-0288606
           (State or other jurisdiction of            (I.R.S. Employer
           incorporation or organization)            Identification No.)
                11030 Roselle Street                        92121
                San Diego, California                    (Zip Code)
      (Address of principal executive offices)

       Registrant's telephone number, including area code: (619) 455-4808

                                -----------------
           Securities registered pursuant to Section 12(b) of the Act:

                                      NONE

           Securities registered pursuant to Section 12(g) of the Act:
                           Common Stock $.01 par value

                         Preferred Stock Purchase Rights
                                (Title of Class)

       Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports) and (2) has been subject to such
filing requirements for the past 90 days. Yes X No __

       Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K is not contained herein, and will not be contained,
to the best of the registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K. __

       The aggregate market value of the voting stock held by non-affiliates 
of the registrant, based upon the closing sale price of the Common Stock on 
February 28, 1999 as reported on the Nasdaq National Market, was 
approximately $84,134,220. Shares of Common Stock held by each executive 
officer and director and by each person who owns 10% or more of the 
outstanding Common Stock have been excluded in that such persons may be 
deemed to be affiliates. This determination of affiliate status is not 
necessarily a conclusive determination for other purposes.

       As of February 28, 1999, there were 12,978,031 shares of the Registrant's
Common Stock outstanding.

                       DOCUMENTS INCORPORATED BY REFERENCE

     Registrant's Proxy Statement to be filed with the Securities and Exchange 
         Commission in connection with the solicitation of proxies for the 
     Registrant's 1998 Annual Meeting of Stockholders to be held on June 9 1999 
       is incorporated by reference in Part III, Item 10 (as to directors), 11, 
                           12 and 13 of this Form 10-K.

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                        BIOSITE DIAGNOSTICS INCORPORATED

                                    FORM 10-K

                                      INDEX

<TABLE>
<CAPTION>
                                                                                           PAGE
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<S>        <C>                                                                             <C>
                                      PART I

Item 1.    Business.....................................................................      1
Item 2.    Properties ..................................................................     29
Item 3.    Legal Proceedings ...........................................................     29
Item 4.    Submission of Matters to a Vote of Security Holders .........................    N/A

                                     PART II

Item 5.    Market for Registrant's Common Equity and Related Stockholder Matters .......     30
Item 6.    Selected Financial Data......................................................     31
Item 7.    Management's Discussion and Analysis of Financial Condition and
           Results of Operations........................................................     32
Item 7a.   Quantitative and Qualitative Disclosures About Market Risk...................     39
Item 8.    Financial Statements and Supplementary Data .................................     39
Item 9.    Changes in and Disagreements With Accountants on
           Accounting and Financial Disclosure..........................................    N/A

                                    PART III

Item 10.   Directors and Executive Officers of the Registrant...........................     40
Item 11.   Executive Compensation.......................................................     41
Item 12.   Security Ownership of Certain Beneficial Owners and Management...............     41
Item 13.   Certain Relationships and Related Transactions...............................     41

                                     PART IV

Item 14.   Exhibits, Financial Statement Schedules, and Reports on Form 8-K.............    42

SIGNATURES .............................................................................    45
</TABLE>

Biosite-Registered Trademark-, Triage-Registered Trademark- and Immediate 
Response Diagnostics-Registered Trademark- are registered trademarks of the 
Company. Omniclonal-TM-, ExpressTest-SM- and the Company's logo are 
trademarks or servicemarks of the Company.

                                       -i-

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                                     PART I

ITEM 1.           BUSINESS

    EXCEPT FOR THE HISTORICAL INFORMATION CONTAINED HEREIN, THE MATTERS
DISCUSSED IN THIS ANNUAL REPORT ON FORM 10-K ARE FORWARD-LOOKING STATEMENTS THAT
INVOLVE RISKS AND UNCERTAINTIES, INCLUDING THE TIMELY DEVELOPMENT, INTRODUCTION
AND ACCEPTANCE OF NEW PRODUCTS, DEPENDENCE ON OTHERS, THE IMPACT OF COMPETITIVE
PRODUCTS, PATENT ISSUES, CHANGING MARKET CONDITIONS AND THE OTHER RISKS DETAILED
THROUGHOUT THIS FORM 10-K. ACTUAL RESULTS MAY DIFFER MATERIALLY FROM THOSE
PROJECTED. THESE FORWARD-LOOKING STATEMENTS REPRESENT THE COMPANY'S JUDGMENT AS
OF THE DATE OF THE FILING OF THIS FORM 10-K. THE COMPANY DISCLAIMS, HOWEVER, ANY
INTENT OR OBLIGATION TO UPDATE THESE FORWARD-LOOKING STATEMENTS.

BACKGROUND

    Biosite Diagnostics Incorporated ("Biosite" or the "Company") develops,
manufactures and markets rapid, accurate and cost-effective diagnostic products
that improve the quality of patient care and simplify the practice of laboratory
medicine. The Company believes that its Immediate Response Diagnostics can have
an important impact on medical decisions, patient care and the cost of medical
treatment. The Company utilizes distributors in the United States and abroad, as
well as a direct sales force, for the distribution of its products to end-users.

    The Company has two product platforms that are designed to provide rapid
results through either qualitative visual readings or quantitative meter
readings. These platforms are based upon the Company's proprietary technologies
in the areas of antibody development, signaling chemistry and micro capillary
fluidics. The Company's testing formats are designed to measure single analyte
targets or multiple analytes simultaneously. They also allow for the analysis of
various sample sources, including urine, serum, plasma, whole blood and stool.

    The Company's first product, the Triage Panel for Drugs of Abuse ("Triage
DOA Panel"), a small self-contained test capable of detecting a broad spectrum
of commonly overdosed prescription and illicit drugs in approximately 10
minutes, is used by approximately 45% of U.S. hospitals. Since its introduction
in 1992, over 8.1 million Triage DOA Panels have been sold worldwide for use in
hospital emergency department screening, occupational health and workplace
testing. The Company estimates that sales to end-users of the Company's Triage
DOA Panel products in 1998 were approximately $43.5 million, and net sales were
approximately $32.2 million in 1998.

    During the first quarter of 1998, the Company received final clearance from
the U.S. Food and Drug Administration ("FDA") to market the Triage Cardiac Panel
and the Triage Meter (together called "Triage Cardiac System") and the Triage C.
DIFFICILE Panel in the United States. The Company began selling the Triage C.
DIFFICILE Panel in March and the Triage Cardiac System in May.

    The Triage Cardiac System is Biosite's first product to utilize the
Company's Triage Meter System technology and is designed to deliver precise,
quantitative results in a rapid timeframe. The Triage Cardiac System aids in the
diagnosis of Acute Myocardial Infarction ("AMI") and provide physicians with an
enhanced ability to make treatment decisions in a timely manner. The Triage
Cardiac System quantitatively measures the level of CK-MB, troponin I and
myoglobin from a whole-blood sample using a single test device. As a result of
manufacturing scale-up and capacity constraint issues related to the production
of the Triage Cardiac System, the Company developed a backlog of orders for the
Triage Cardiac System during the third and fourth quarter of 1998. The Company
addressed manufacturing scale-up and capacity constraint issues related to the
production of the Triage Cardiac system and filled the backlog orders during
December 1998 and the first quarter of 1999.

    The Triage C. DIFFICILE Panel is a rapid test designed to identify
CLOSTRIDIUM DIFFICILE, an opportunistic pathogen of the intestinal tract that
may thrive as a result of broad spectrum antibiotic treatment.

    In October 1998, the Company received final clearance from the FDA to market
the Triage Parasite Panel, the Company's third product launched in 1998. The
Triage Parasite Panel is a rapid test designed to simultaneously detect three
common waterborne parasites, GIARDIA LAMBLIA, CRYPTOSPORIDIUM PARVUM and
ENTAMOEBA HISTOLYTICA/DISPAR, that can cause severe gastrointestinal infections.
Sales of the Triage Parasite Panel were initiated

                                      -1-

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in mid-October.

    The Company uses the Fisher Healthcare division ("Fisher," formerly the 
Curtin Matheson Scientific division) of the Fisher Scientific Company to 
distribute its products to the hospital market segment in the United States 
and country-specific and regional distributors to market the products in 
countries in Europe, Latin America, the Middle East, Asia and Africa.

    The Company is developing several additional products for applications 
where the Company believes its Immediate Response Diagnostics can play an 
important role in improving patient care. Products under development include 
tests that are intended to aid in the diagnosis of congestive heart failure 
and sepsis or bacteremia, the dosing of certain therapeutic drugs and the 
detection of certain bacterial infections.

The Company has entered into agreements with pharmaceutical and diagnostic 
companies, including Novartis Pharma AG ("Novartis,") for the development of 
a product to monitor the concentrations of the immunosuppressant drug, 
cyclosporine; and Scios Inc ("Scios") for the development of a product to be 
used in the diagnosis of congestive heart failure; and XOMA Corporation 
("Xoma") for the development of a product to be used in the diagnosis of 
sepsis or bacteremia. The products covered by these arrangements are under 
development and have not generated any revenue from product sales for the 
Company.

    In March 1999, the Company introduced its Biosite Discovery program, a 
collaborative research and diagnostics development program focused on the 
identification of new protein markers for acute diseases. The Company will 
seek to use its expertise in antibody development to help pharmaceutical and 
biotechnology partners accelerate their research programs. In return, Biosite 
intends to obtain diagnostic rights to the proteins under study. Biosite will 
utilize its proprietary Omniclonal antibody development technology to develop 
high affinity antibodies for the characterization and validation of protein 
targets. Initially, Biosite will focus on disease target markers in four core 
areas: cardiovascular, cerebrovascular, infectious disease and oncology. If 
the diagnostic utility of a marker is established, it will then be assessed 
for commercialization potential, with high value markers being added to 
Biosite's product development pipeline. The Company executed its first 
collaborative agreement under the Biosite Discovery program in the 
cardiovascular area with Scios in November 1998.

INDUSTRY OVERVIEW

    In 1998, the worldwide market for immunoassays exceeded $3.9 billion, 
consisting primarily of testing related to infectious disease, endocrinology, 
therapeutic drug monitoring, drugs of abuse testing, immunology/allergy, 
tumor markers and blood typing. The global market for immunoassays continues 
to expand as new disease states are identified, new therapies become 
available, and worldwide standards of living and access to health care 
improve. Such tests are performed primarily in hospital-based laboratories 
and commercial laboratories, which account for approximately 80% of all 
diagnostic tests performed annually. In recent years, diagnostic tests that 
can be performed nearer to the point of patient care have emerged as an 
important tool in disease diagnosis and management.

    Immunoassays were first developed based on technology developed in the 
1960s. Although early immunoassays offered unprecedented levels of 
sensitivity for the detection of low concentration analytes, they suffered 
from relatively short shelf-lives, long reaction times, a need for 
radioactive labels to detect completed reactions and lack of consistent 
results among products from different suppliers. Over time, technological 
advances such as the introduction of monoclonal antibodies, enzyme and 
fluorescent labels and various solid phase formats shortened immunoassay 
reaction times, provided higher specificity and allowed the development of 
tests with longer shelf-lives and greater consistency.

    These advances also led to the development of immunoassay analyzers, testing
systems utilizing automated liquid handling mechanisms and pipetting systems for
reagent addition. Modern immunoassay analyzers are capable of storing and
selecting multiple reagents for a variety of analytes, including drugs, hormones
and cancer antigens. They also provide accurate and highly sensitive test
results and help to simplify the performance of immunoassays. However,
immunoassay analyzers are large and complex, may have lengthy turnaround times
and require high volumes of sample throughput to justify the investment in
equipment, training, staffing and other costs required to operate and support
the systems. Even those systems with rapid onboard turnaround times require
transport of the

                                      -2-

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sample to the testing lab and preparation of the samples to obtain serum or 
plasma, which can be time consuming.

    In recent years, there has been a continuing shift from the use of such 
conventional analyzer systems to more technologically advanced rapid testing 
methods that can be performed in minutes by less skilled personnel. Simple, 
rapid immunoassays are capable of detecting a single analyte target with a 
color change that can be visually interpreted. Formats such as dipsticks, 
test tubes and membrane test cartridges have been used to provide fast, 
non-instrument read results for conditions where a single analyte target is 
present in high concentrations and where a simple yes/no non-numeric answer 
is clinically relevant. Rapid color change test formats are widely available 
for drugs of abuse, pregnancy, strep throat and ovulation prediction. Until 
recently, simple test formats have remained incapable of precise, 
multi-analyte detection or highly sensitive, quantitative measurements. As a 
result, medical conditions where the detection of one or more analytes is 
required or where the precise quantitation of the target analyte is required 
have remained the domain of immunoassay analyzers.

    The Company believes that there is significant market potential for 
advanced rapid diagnostic products. Rapid testing, including point-of-care 
testing, helps to reduce overall health care delivery costs and can improve 
patient outcomes by providing diagnosis during the patient visit, thereby 
minimizing the time to medical intervention and reducing the need for 
additional patient follow-up. Patients undergoing emergency procedures can 
benefit from more timely and accurate testing results, both to ensure correct 
decision making and to avoid unnecessary use of costly inpatient care. 
Disease management programs such as therapeutic drug monitoring programs can 
benefit from real-time, point-of-care evaluations that enable care-givers to 
optimize drug dosing. Quicker diagnosis of infectious agents can also permit 
earlier prescription of appropriate medications, potentially shortening the 
duration of illness.

TECHNOLOGY

    Biosite's Immediate Response Diagnostics technology is based on several 
proprietary advances in the biological and physical sciences that make 
practical the development and manufacture of rapid, accurate and 
cost-effective point-of-care diagnostics. The Company's products integrate 
its expertise in several core scientific and engineering disciplines, 
including antibody development and engineering, analyte cloning and 
synthesis, signaling chemistry and micro capillary fluidics, each of which is 
described below. Biosite's research and development program is supported by 
75 employees, including 17 Ph.D.s with expertise in the Company's core 
technologies. By combining research capabilities in each of these areas, 
Biosite is able to create novel single and multi-analyte diagnostics which 
overcome the limitations of traditional rapid diagnostic technologies and 
seek to address the significant unmet need for effective point-of-care 
diagnostic information.

  ANTIBODY DEVELOPMENT AND ENGINEERING

    Biosite believes that its internal antibody development and engineering 
capabilities allow rapid identification and development of antibodies with 
optimal specificity, affinity and stability characteristics. The Company 
initially utilized hybridoma technology for the selection and production of 
its novel antibodies. Three disadvantages of hybridoma technology are the 
length of time required to develop antibody candidates, the higher costs 
associated with the use of this technology and the need to restart the 
antibody development process when unwanted characteristics such as cross 
reactivities are discovered. The Company has developed a proprietary process 
utilizing phage display of antibodies that enables the selection and 
production of antibodies more rapidly and efficiently than is possible using 
hybridoma technology. In addition, Biosite has isolated the genes encoding 
the antibodies that permit the genetic engineering of antibodies. As a 
result, Biosite can alter or add specific amino acids or polypeptides in an 
antibody in order to improve the antibody's specificity and to facilitate 
purification of the antibody. This technology accelerates the antibody 
selection process by rapidly eliminating unwanted cross reactivities 
discovered in product development.

  ANALYTE CLONING AND SYNTHESIS

    The Company has molecular biology capabilities that include the cloning 
and identification of specific proteins useful in the development of 
immunoassays. Biosite has developed proprietary expression vectors that 
enable the production and purification of these proteins for the development 
of antibodies and for use as calibrators and controls in its immunoassay 
products. In addition, the Company has considerable expertise in synthetic 
organic chemistry which allows the synthesis of targets and useful 
derivatives. The Company develops products for which the targeted analyte can 
be small (i.e., haptens, such as drugs) or large (i.e., proteins, such as 
cardiac enzymes). The Company believes that the ability to develop, stabilize 
and manufacture the target analyte or its analogues is key to the

                                      -3-

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development of highly accurate immunoassays.

  COLOR/PHOTOCHEMICAL SIGNALING

    Immunoassays require the attachment of a detectable label to an antibody 
or target analyte. The Company has developed a variety of labels for the 
development of its products. For yes/no tests, a visual label that produces 
color is attached to antibodies or analytes through either non-covalent or 
covalent chemical methods. For its quantitative products, the Company has 
developed novel fluorescent dyes which are attached to antibodies or analytes 
using both noncovalent and covalent chemical means. Although fluorescence is 
a potentially powerful label for use in immunoassays, its potential has been 
limited by the lack of available dyes that are stable and have no sample 
interference, and the requirement of a complex instrument for detection. The 
Company's novel fluorescent dyes are stable and exhibit properties that 
permit their use in complex biological samples such as serum, plasma and 
whole blood without interference from the sample. Furthermore, these novel 
dyes absorb light at wavelengths where a simple instrument can be used to 
excite and detect fluorescence for quantitative measurements.

  MICRO CAPILLARY TEST DEVICE TECHNOLOGY

    Biosite has developed proprietary technology to design, develop and 
manufacture devices containing micro capillaries to control the flow of 
fluids in immunoassay processes. The qualitative device format uses micro 
capillaries to draw fluids through a membrane that contains immobilized 
antibody zones for the detection of specific substances. The quantitative 
device format uses several different micro capillary designs to control the 
contact of sample with reagents and to control the flow of fluid throughout 
the device. When sample is added to the quantitative device, a filter 
contained within the device separates blood cells from plasma which is 
further directed by capillary forces into a chamber that contains dried 
immunoassay reagents. After an incubation time that is determined by another 
micro capillary element of the device, the volume of sample that contacted 
the reagents flows down a capillary path that brings it into contact with 
immobilized antibody zones. The binding of fluorescent reagents at these 
zones is detected by an instrument and is related to the concentration of the 
substance being tested for in the sample. The Company has also developed the 
engineering capability to design unique micro capillary structures in plastic 
parts and to fabricate them in commercial scale quantities using injection 
molding processes.

 SAMPLE HANDLING

    The Company has developed proprietary technology relating to sample 
handling and preparation, including technology that allows whole blood to be 
passively separated into its plasma component or to be passively lysed to 
release the target analyte. The Company has also developed technologies for 
the handling of stool samples which concentrate and purify the target 
analytes or organisms from solid stool materials. In addition, the Triage 
Panel platform can be used to assay urine samples.

BIOSITE DISCOVERY PROGRAM

    In March 1999, the Company introduced its Biosite Discovery program, a 
collaborative research and diagnostics development program focused on the 
identification of new protein markers for acute diseases. The Company will 
seek to use its expertise in antibody development to help pharmaceutical and 
biotechnology partners accelerate their research programs. In return, Biosite 
intends to obtain diagnostic rights to the proteins under study. Biosite will 
utilize its proprietary Omniclonal antibody development technology to develop 
high affinity antibodies for the characterization and validation of protein 
targets. The Omniclonal technology combines antibody phage display 
capabilities and a highly efficient antibody expression and purification 
process. Initially, Biosite will focus on disease target markers in four core 
areas: cardiovascular, cerebrovascular, infectious disease and oncology. 
Biosite has invested in a high throughput robotic immunoassay analyzer that 
is capable of performing an immunoassay for up to 10,000 serum or plasma 
samples in a 24-hour period. Biosite intends to use this high throughput 
immunoassay system and the Omniclonal antibodies developed for potential 
diagnostic markers to detect the markers in a large population of clinical 
samples from patients with diseases in our core areas of interest as well as 
normal, healthy people. The results of this analysis may establish the 
diagnostic sensitivity and specificity of the potential markers for specific 
diseases. If the diagnostic utility of a marker is established, it will then 
be assessed for commercialization potential, with high value markers being 
added to Biosite's product development pipeline. The Company executed its 
first collaborative agreement under the Biosite Discovery program in the 
cardiovascular area with Scios in November 1998.

                                      -4-

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PRODUCT PLATFORMS

    The Company has used its core technologies to develop two product 
platforms: the Triage Panel and the Triage Meter System. Both of the 
Company's product platforms utilize the Company's expertise in antibody 
engineering, analyte cloning, signaling chemistry, micro capillary fluidics 
and sample handling technologies.

  TRIAGE PANEL

    The Triage Panel platform is designed for rapid, qualitative screening of 
multiple analytes in a small single-use device. The Triage Panel has a visual 
(yes/no) display containing simultaneous tests for any combination of 
analytes and control standards up to a total of ten. It can be performed in a 
simple multi-step process, and is capable of performing tests on both urine 
and stool. The Triage DOA Panel, the first product developed on this 
platform, tests for up to eight abused drugs analytes in approximately 10 
minutes. The Triage C DIFFICILE Panel and the Triage Parasite Panel test for 
the detection of microorganisms that cause severe gastrointestinal disease. 
The Company is currently developing one other application for this platform, 
the Triage Enteric Panel, which would test for the detection of certain 
common enteric bacteria responsible for food poisoning.

  TRIAGE METER SYSTEM

The Triage Meter System platform is designed to provide rapid quantitative 
results for immunoassays in whole blood, serum and plasma. The Triage Meter 
System consists of two parts: a small single-use disposable test cartridge 
and a proprietary, compact, point-of-care, fluorescent meter. After a blood 
sample is applied to the cartridge, the cartridge is inserted into the meter, 
which is designed to automatically and simultaneously detect up to six 
analytes and display the results on a numerical electronic read-out. The 
meter incorporates proprietary software in erasable, programmable, read-only 
memory ("EPROM") chips which are intended to be plugged into each meter. The 
software may also provide important information regarding the analyte 
measured, such as normal or abnormal levels of a marker which could then be 
used to initiate therapy or manage patient disease. Studies have validated 
that the analyte measuring sensitivity of the Triage Meter System products is 
comparable to the sensitivity levels of the conventional immunoassay 
analyzers. The Triage Cardiac System is the first of the Company's 
commerialized products developed under this platform. The Company is 
developing three other applications for this platform: 1) the NeoralChek 
System, a product for the monitoring of the concentration of cyclosporine, an 
immunosuppressant drug prescribed to prevent organ rejection in organ 
transplant recipients. 2) the Triage BNP Assay, a product to be used as an 
aid in the diagnosis of congestive heart failure, and 3) the Triage LBP 
Assay, a product to assist in the diagnosis of sepsis or bacteremia.

PRODUCT ATTRIBUTES

    Although the Company's commercial products and products under development 
are based upon the Triage Panel and Triage Meter System platforms and utilize 
different technologies, they share common attributes which the Company 
believes make them superior to conventional immunoassay analyzers:

         -        RAPID RESULTS:  The Company's products and products under
                  development are designed to offer complete results in a rapid
                  timeframe .

         -        EASE OF USE: The Company's products and products under
                  development are designed to be simple to use. The Triage DOA
                  Panel has only three steps while the Triage Meter System
                  products are expected to require only one assay step.

         -        HIGH ANALYTICAL ACCURACY:  The Company develops and uses high
                  quality biological and chemical reagents to yield highly
                  specific, accurate and reproducible analytical results.

         -        CAPABILITY OF PERFORMING MULTIPLE ANALYSES: The Company's
                  products and products under development are designed to
                  measure one or more target analytes simultaneously, including
                  reagent controls, without sacrificing the quality of the
                  individual analysis. This simultaneous detection capability
                  can provide significant time and cost savings compared to
                  current technologies.

                                      -5-

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         -        RELIABILITY: Biosite's use of internal thresholds, built-in
                  controls, software lockouts and other controlling mechanisms
                  are intended to make its current and future products extremely
                  reliable in any hospital or clinical laboratory setting.

         -        COST EFFECTIVENESS: The Company's products and products under
                  development are designed to simplify the performance of highly
                  complex testing procedures and significantly reduce the cost
                  of testing, equipment acquisition and maintenance, making them
                  cost-effective alternatives to conventional immunoassay
                  analyzers.

PRODUCTS AND PRODUCTS UNDER DEVELOPMENT

    The Triage DOA Panel was introduced in 1992 and has been used by hospital 
labs and emergency departments to screen for up to eight commonly abused 
prescription and illicit drugs or drug classes. During 1998, the Company 
began commercialization of three new products, the Triage C. DIFFICILE Panel, 
Triage Parasite Panel and Triage Cardiac System.

    The Company has four additional products under development (Triage 
Enteric Panel, NeoralChek System, Triage BNP System and Triage LBP System) 
which apply the Company's Immediate Response Diagnostics technologies to a 
variety of other medical testing needs. The Company continues to evaluate 
other rapid diagnostic product opportunities that can utilize the Company's 
technologies.

    The Company intends, where appropriate, to enter into licensing and/or 
collaborative arrangements to develop and commercialize additional future 
products. The Company may not be able to negotiate license or collaborative 
arrangements on favorable terms, if at all, in the future, or that its 
current or future licensing or collaborative arrangements will be successful.

TRIAGE PANEL FOR DRUGS OF ABUSE

    The Company believes the U.S. market for abused drug testing is 
approximately $628 million annually.  The U.S. market can be divided into 
four major categories:

         -        MEDICAL TESTING: The medical testing segment represents
                  testing typically performed in a hospital laboratory. The
                  results are generally reported to emergency physicians and
                  psychiatrists. Such tests have the highest need for rapid
                  turnaround of results, and generally have the highest cost per
                  result.

         -        NON-MEDICAL TESTING: The non-medical testing market consists
                  of testing performed for the workplace, the criminal justice
                  setting and drug rehabilitation centers. Testing may be
                  performed on-site or at an occupational health provider, but
                  generally samples are sent to independent reference
                  laboratories. The demand for a rapid result varies by type of
                  industry, but typically is not quite as great as in the
                  medical segment. Additionally, the cost per result is slightly
                  reduced.

         -        REFERENCE LABORATORY TESTING:  The reference laboratory
                  testing market accounts for a significant percentage of the
                  total drug testing market.  The majority of samples come from
                  the non-medical testing market, although some smaller
                  hospitals in the medical testing market also send their
                  samples to reference laboratories.  In general, results are
                  not available for at least 24 hours from the time the specimen
                  is collected.  Despite relatively long turnaround times, the
                  reference laboratory market has remained substantial because
                  of its ability to produce results on a low cost per panel
                  basis and reduce the potential liability associated with
                  workplace testing.

HOSPITAL/EMERGENCY DEPARTMENT

    Drug abuse plays a significant role in emergency medicine cases occurring
annually in the United States, either as a primary cause such as an overdose, or
as a contributing factor such as in the case of an accident. A diagnostic
dilemma confronts physicians when a patient is presented with symptoms that
could either be drug related or non-drug related. A patient brought to a
hospital emergency department in a coma may be under the influence of narcotics

                                      -6-

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or sedatives, which may require one type of treatment or intervention. 
Conversely, the same patient may have had a stroke or suffered some form of 
trauma requiring a completely different type of care. The ability to obtain a 
differential diagnosis in a timely manner greatly aids the course of 
treatment.

    Prior to the introduction of the Triage DOA Panel, drug or toxicology 
screening was accomplished by several technologies, primarily automated 
immunoassays and Gas Chromatography/Mass Spectroscopy ("GC/MS"). Although 
GC/MS is the most specific identification method commercially available, it 
is time consuming (requiring an average of approximately three hours per 
test), complex and expensive, and is generally reserved for final 
confirmation of specimens that have been screened positive by an immunoassay. 
Automated immunoassays, although less expensive than those performed by 
GC/MS, also require significant amounts of time (approximately one to two 
hours) because of the necessity of performing analyses of several drugs 
sequentially on each patient specimen. Additionally, in many cases the 
equipment required to perform an immunoassay is not accessible on an 
immediate or rapid basis.

    The Triage DOA Panel is a rapid qualitative urine screen that analyzes a 
single test sample for up to eight different illicit and prescription drugs 
or drug classes and provides results in approximately 10 minutes. The Triage 
DOA Panel is instrument independent, contains built-in controls for accuracy 
and is capable of a high degree of specificity. Illicit drugs detected by the 
Triage DOA Panel include: Amphetamines/Methamphetamines (speed, crystal), 
Cocaine (crack), Opiates (heroin), Phencyclidine (angel dust), 
Tetrahydrocannabinol (pot, marijuana), while prescription drugs tested by the 
Triage DOA Panel include Barbiturates (Phenobarbital), Benzodiazepines 
(Valium, Librium, Halcion), Tricyclic Antidepressants (Elavil, Tofranil) and 
Methadone. The Triage DOA Panel is configured to test various combinations of 
the foregoing drugs. In February 1995, the Company launched the Triage DOA 
Plus TCA Panel, a configuration which includes a test for Tricyclic 
Antidepressants ("TCA") which otherwise requires a separate blood test. Since 
its introduction in February 1992, the Company has sold over 8.1 million 
Triage DOA panels worldwide, and approximately 45% of hospitals in the United 
States use the product.

    The Company distributes the Triage DOA Panel products in the U.S. 
hospital market segment through Fisher. Other country-specific and regional 
distributors sell the Triage DOA Panel products in certain countries in 
Europe, Latin America, the Middle East, Asia and Africa.

WORKPLACE SCREENING

    New hires in major U.S. firms may be screened for drug usage as part of 
pre-employment physicals. The majority of these test samples are sent to 
centralized reference laboratories that could provide both the initial 
immunoassay screening result and the confirmation of presumptive positive 
results by an alternate method, such as GC/MS. Testing of government and 
certain government regulated employees and contractors must be performed at 
SAMHSA certified reference laboratories. Employers that are not government 
contractors send their drug screens to their laboratory of choice or perform 
on-site testing. Non-SAMHSA testing is estimated to account for over eight 
million tests performed annually.

    The majority of employers with drug screening programs have chosen not to 
implement "on-site" testing in their facilities due to costly personnel and 
regulatory burdens on an employer's in-house testing laboratory. These 
industrial testers, however, still have a need for rapid results since many 
employment decisions hinge on an employee's ability to pass physical and 
other examinations that include a test for illegal drugs. Despite this need 
for rapid results, there is a 24 to 48 hour wait based on the sample 
transportation and testing process used by major reference laboratories. 
Therefore, an immunoassay that provides rapid results, such as the Triage DOA 
Panel, can get employees back to work quickly and save employers' money.

    The Company established the ExpressTest One-Hour Drug Screen service, a 
marketing program initiated in conjunction with regional providers of 
occupational health services, as a means of expanding the market for the 
Triage DOA Panel. The ExpressTest program incorporates the Company's 
"near-site" testing strategy, using the Triage ExpressTest Panel (a test for 
five illicit drugs or drug classes) to provide the benefits of rapid drug 
test results without requiring employers to set up an on-site laboratory. 
Participating occupational health clinics provide rapid results to industrial 
clients that send prospective employees to them for pre-employment physicals 
and drug screens. Biosite's sales force actively supports these selected 
occupational health clinics in their marketing of the ExpressTest program to 
potential industrial clients in their regional areas.

                                      -7-

<PAGE>

THE TRIAGE CARDIAC SYSTEM

    The Company has estimated that, in 1998, over six million people in the 
United States visited hospital emergency departments with complaints of chest 
pain. Of those, approximately 650,000 were diagnosed with AMI and 
approximately 800,000 were diagnosed with unstable angina. In total, 
approximately 1.9 million of the patients who present with chest pain were 
admitted to coronary care units. Of these, approximately 30,000 to 60,000 
patients were misdiagnosed as not having an AMI. Additionally, approximately 
450,000 of these patients who did not have an AMI were admitted to hospitals 
and ultimately released within two days. The Company believes that rapid, 
quantitative results for multiple cardiac markers provided at the 
point-of-care may have a positive impact on misdiagnosed AMI, and may provide 
substantial benefits to patients and savings to the hospital.

    AMI is generally caused by the blocking or "occlusion" of an artery 
providing oxygen-enriched blood to the heart. Without oxygen, the heart 
muscle is destroyed, with prolonged occlusion resulting in additional muscle 
damage. The destruction of cells in the heart muscle results in the release 
of several markers into the bloodstream, including CK-MB, troponin I and 
myoglobin.

    Clinicians generally rely on patient history, electrocardiograms and 
serial measurement of CK-MB for early diagnosis of AMI. Troponin I and 
myoglobin are also emerging as useful adjuncts to CK-MB in the detection of 
heart attacks. The Company believes that the concentrations of these three 
markers typically peak and fall over different time periods and that 
simultaneous measurement of these markers is a more accurate diagnostic 
technique for AMI than the measurement of any one single marker. Studies have 
shown that serum concentrations of myoglobin are elevated most quickly 
post-AMI. Additionally, in patients presenting within 12 hours of AMI symptom 
onset, quantitative serial measurement of myoglobin has demonstrated 
significantly higher sensitivity in diagnosing AMI than CK-MB. Troponin I has 
been shown to maintain an elevated concentration for a longer period of time 
than CK-MB and myoglobin.

    Several diagnostic tests have recently been developed to quantitatively 
measure the blood levels of such markers. Unfortunately, the quantitative 
measurement of multiple markers currently requires large, centralized 
immunoassay systems that cannot directly analyze whole blood and are not 
always available on a rapid basis. Additionally, these systems require 
multiple reagent packs, as well as frequent standardization and quality 
control. Since turnaround time for such test results is critical, current 
immunoassay systems may not satisfy physician needs.

The Company believes that a rapid, point-of-care test capable of 
quantitatively measuring multiple markers of an AMI would have a positive 
impact on patient care. Accordingly, the Company's Triage Cardiac System is 
designed to quantitatively measure the levels of CK-MB, troponin I and 
myoglobin in a single test device from a whole-blood sample. The Triage Meter 
System is designed to provide quantitative results of these measurements at 
or near the point-of-care and may aid in the detection of AMI by providing 
point-of-care quantitative results, enabling physicians to make treatment 
decisions in a timely manner. The Company utilizes both distributor alliances 
and a direct sales force in marketing the Triage Cardiac System.

THE TRIAGE C. DIFFICILE PANEL

    CLOSTRIDIUM DIFFICILE ("C. DIFFICILE") is an opportunistic pathogen of 
the intestinal tract that may thrive as a result of broad spectrum antibiotic 
treatment. The bacteria may be found in asymptomatic carriers or may spread 
among immunocompromised hospital patients. Toxins produced by the bacteria 
mediate C. difficile-associated disease ("CDAD"), which may include 
antibiotic-associated diarrhea and antibiotic-associated pseudo-membranous 
colitis. Due to the potential spread of infection, patients identified as 
possibly having CDAD are usually placed in isolation until the infection is 
controlled. Symptoms of CDAD include diarrhea as well as fluid and weight 
loss. It has been estimated over 3.0 million rapid tests for C. DIFFICILE 
were performed annually in the United States. This number is expected to 
continue to rise due to the expected increase in the number of patients who 
are immunocompromised.

    Historically, the use of a cytotoxin test, which takes 2 to 48 hours to 
produce diagnostic results, was the only means to identify the toxin 
associated with C. DIFFICILE. More recently, in response to the need for more 
rapid identification of the C. DIFFICILE toxin, several manufacturers have 
developed and marketed enzyme-linked immunosorbent assays ("ELISA") that can 
be performed in one to two hours. These ELISA test formats are increasingly 
used by hospitals testing for the toxin.

                                      -8-

<PAGE>

    Although the ELISA technology is significantly faster than the cytotoxin 
test, it still requires several precisely timed steps as well as multiple 
standards every time the test is performed, making it unlikely that the 
testing will be done when an individual specimen is sent to the laboratory. 
The multiple standards and quality controls required with each run make the 
processing of individual specimens expensive. As a result, specimens are 
generally only processed in "batch" mode, delaying the diagnostic result, and 
limiting the information available to a physician evaluating therapeutic 
measures.

    The Triage C. DIFFICILE Panel is designed to simplify the laboratory 
procedure and improve the turnaround time for a physician to receive a result 
by enabling laboratories to complete direct testing for the bacteria, as well 
as testing for the toxin in less than 20 minutes. The Triage C. DIFFICILE 
Panel is also designed to provide a negative predictive value that is 
superior to that of existing immunoassays by coupling the results of direct 
organism detection with toxin detection. Since the test is being designed 
with built-in controls and standards, it may be performed individually or in 
batches, by any laboratory technician, without compromising the quality of 
the result. By improving the turnaround time to result, the clinician may 
initiate therapy earlier and thus minimize a patient's time in isolation. 
Rapid, accurate diagnosis of the bacteria and toxin should enable earlier 
treatment, which may reduce length of stay in the hospital and may reduce 
cost. The Company utilizes distributor alliances in marketing the Triage C. 
DIFFICILE Panel.

 THE TRIAGE PARASITE PANEL

    Parasitic infection is a common cause of gastrointestinal disease and 
diarrhea. Some of the more common parasites responsible for such infection 
are GIARDIA LAMBLIA ("GIARDIA"), CRYPTOSPORIDIUM PARVUM ("C. PARVUM"), 
ENTAMOEBA HISTOLYTICA and microsporidia species. According to the U.S. Center 
for Disease Control and Prevention ("CDC"), intestinal parasitic infection is 
a problem in the United States and that the prevalence of GIARDIA may be 
increasing.

    The most commonly employed method of detecting parasites from stool 
samples is by a cumbersome ova and parasite ("O&P") microscopic examination, 
typically of three consecutive stool specimens from the patient. The 
preparation of the sample by a laboratory technologist involves stool 
specimen dilution and the preparation of multiple microscope slides. Each 
slide must then be observed via microscope by a technologist trained in the 
identification of parasites. The time to diagnose parasitic infection is 
prolonged due to the need for microscopic examination of multiple stool 
specimens per patient. The prolonged time required to obtain results may 
delay the treatment of patients.

    It is estimated that in 1998 approximately 1.0 million O&P microscopic 
examinations were performed in the United States. Because of the cumbersome 
procedures and limited test menu of the current ELISA test formats, these 
tests have had limited success in hospitals that perform larger volumes of 
tests in batches. Recently, several manufacturers have developed and marketed 
ELISA tests for the more rapid identification of two of the more common 
parasites, GIARDIA and C. PARVUM.

    The Triage Parasite Panel is designed to replace the standard O&P 
microscopic detection method for three of the most commonly encountered 
parasites: Giardia, C. parvum and Entamoeba histolytica/dispar in a single 
test device. Because each test device includes controls, the product may be 
used for any volume of tests. The Triage Parasite Panel makes rapid results 
(less than 20 minutes) available to hospitals of any size, including 
facilities that previously sent such testing to a reference lab. The 
sensitivity of the Triage Parasite Panel is comparable to that of the current 
O&P microscopic examination, using only a single patient specimen. This 
should greatly reduce the collection burden for the patient, and reduce the 
amount of labor for the laboratory technician. Additionally, the length of 
time physicians spend waiting for results may be reduced. The Company 
utilizes distributor alliances in marketing the Triage Parasite Panel. Sales 
of the Triage Parasite Panel are expected to be seasonal in nature as 
parasitic infections are less prevalent during the colder seasons of the year.

THE TRIAGE ENTERIC PANEL

    Gastroenteritis, commonly described as "food poisoning," often occurs 
among individuals who have consumed contaminated food or water or have been 
exposed to stool contaminated with microorganisms such AS SALMONELLA, 
CAMPYLOBACTER JEJUNI/COLI, SHIGELLA and ENTEROHEMORRHAGIC E. COLI. Eight to 
24 hours after such exposure, individuals may experience abdominal pain, 
nausea and diarrhea. It is estimated that in the United States approximately 
3.0 million stool cultures are performed annually for the diagnosis of food 
poisoning. Microorganisms

                                      -9-

<PAGE>

are often implicated in such cases.

    Stool culture, currently the primary method of diagnosing food poisoning, 
involves the inoculation of multiple culture plates with stool specimen. 
After 24 to 48 hours, culture plates that exhibit bacterial growth are 
subjected to biochemical tests that typically take an additional 24 hours. As 
a result of the prolonged testing procedure, physicians generally wait 48 to 
72 hours for test results.

    The Triage Enteric Panel is being developed for identification of the 
most common enteric bacteria responsible for food poisoning such as 
SALMONELLA, CAMPYLOBACTER JEJUNI/COLI, SHIGELLA and ENTEROHEMORRHAGIC E. 
COLI. The Triage Enteric Panel would enable the laboratory technician to 
rapidly detect the presence of such enteric bacteria from a stool specimen. 
This should greatly reduce the amount of labor required of laboratory 
technicians, thereby reducing costs. Additionally, results can be returned to 
the physician in a shorter period of time.

    The Triage Enteric Panel is in the development stage.

THE NEORALCHEK SYSTEM

    Transplants of human organs require suppression of the organ recipient's 
immune system. Cyclosporine is the most widely used pharmaceutical for such 
purposes, with annual worldwide sales in excess of $1.3 billion. Cyclosporine 
is chronically administered to patients who have received an organ 
transplant. Over 20,000 patients undergo organ transplantation in the United 
States annually. In excess of 200,000 organ recipients worldwide take 
immunosuppressant drugs on a daily basis. Novartis is the developer and 
leading supplier of cyclosporine, and is involved in several collaborations 
in the organ transplant field including health care management, 
xenotransplantation, and near-patient testing in an effort to support the use 
of organ transplantation.

    The blood level of cyclosporine must be monitored to ensure that a 
patient receives the appropriate therapeutic dose while minimizing toxicity. 
Patients receiving cyclosporine must maintain a minimum concentration of the 
drug that enables it to be effective, yet maintain a level that is low enough 
not to be toxic. This range is often referred to as the therapeutic window. 
Physicians primarily rely on large, centralized laboratories to measure 
cyclosporine blood levels. The physician typically does not receive test 
results for at least 4 to 48 hours, requiring a call back to the patient if 
the dose of the drug needs to be adjusted. A smaller share of cyclosporine 
testing is performed by high performance liquid chromatography ("HPLC"). The 
current worldwide market for cyclosporine testing by immunoassay is estimated 
to be over 5 million tests per year. Patients are monitored frequently in the 
immediate post-transplant time frame with reduced, but continued testing, 
averaging four times per year, for the remainder of the patient's lifetime.

    The NeoralChek System (consisting of the NeoralChek Assay and the Triage 
Meter) is designed to enable a physician to easily, rapidly and accurately 
measure cyclosporine levels. The NeoralChek System is being developed to 
provide a cost-effective means of determining cyclosporine levels on a 
real-time basis in order to enable physicians to optimize drug therapy during 
a patient's visit. As part of its research and development collaboration with 
Novartis, Biosite has obtained licenses to certain technology that makes 
rapid analysis of cyclosporine levels possible. See "-- Strategic and 
Distribution Arrangements."

The NeoralChek System is in the development stage. If successfully developed 
and approved for commercialization, the Company expects Novartis to support 
the promotion of the NeoralChek System worldwide. The Company successfully 
completed feasibility studies for the NeoralChek System under its antibody 
license agreement with Novartis. Additionally, the Company and Novartis 
expanded the scope of their collaboration to include the development of a 
second version of the NeoralChek System. The attainment of certain milestones 
under the expansion of the collaboration resulted in contract revenues of 
$1.1 million during 1998. Additional payments to Biosite will be made if 
certain milestones are achieved. The Company initiated clinical trials for 
both versions of the NeoralChek System in June and July 1998. The clinical 
trials were suspended in September 1998 to permit the Company to make 
improvements to the NeoralChek System. The clinical trials may resume in the 
first half of 1999.

THE TRIAGE BNP SYSTEM

    Congestive Heart Failure ("CHF") is a chronic inability of the heart to
maintain an adequate output of blood from one or both ventricles of the heart,
resulting in congestion or swelling of certain veins or organs, and an
inadequate

                                      -10-

<PAGE>

blood supply to the body. It is estimated that approximately 400,000 new 
cases of CHF occur each year. Current testing methods used in diagnosing CHF 
include electrocardiograms, chest x-rays, echocardiography, and the analysis 
of blood gases and electrolytes.

    The Company has obtained a license to technology and patents developed by 
Scios, Inc. for use in developing an assay for the diagnosis of congestive 
heart failure by monitoring levels of B-type Natriuretic Peptide ("BNP"), a 
hormone made primarily in the ventricles of the heart. Studies suggest that 
levels of BNP become elevated in circulating blood plasma during heart 
dysfunction associated with congestive heart failure in both symptomatic and 
asymtomatic patients.

    The Triage BNP System (consisting of the Triage BNP Assay and the Triage 
Meter) is designed to enable a physician to easily, rapidly and accurately 
measure BNP levels. The Triage BNP System is being developed to provide 
physicians with a cost-effective means of determining BNP levels at the 
point-of-care and aid in the diagnosis of congestive heart failure and assist 
in the differentiation of CHF from other conditions with similar clinical 
symptoms. Additionally, by providing physicians with a convenient means of 
monitoring BNP levels in CHF patients, the Triage BNP Assay may aid in the 
evaluation of the effectiveness of therapies utilized in CHF patient care. 
The Company initiated clinical trials for the Triage BNP System in December 
1998. The Company may not successfully develop or introduce any products 
based upon the Scios-licensed technology.

THE TRIAGE LBP SYSTEM

    Sepsis occurs when the bloodstream is infected by gram-negative bacteria. 
An inflammatory reaction initiated by these bacteria and their associated 
endotoxin can cause widespread damage to blood vessels leading to circulatory 
shock, organ failure, gangrene of extremities and death. The complications 
associated with sepsis can advance rapidly.

    Biosite has obtained a U.S. license to certain technology and patents 
developed by XOMA Corporation related to methods of measuring levels of 
Lipopolysaccharide Binding Protein ("LBP") in human blood. Studies suggest 
that levels of LBP become elevated as a specific response to endotoxin, a 
poisonous component of gram-negative bacteria. Biosite is using this 
technology to develop a diagnostic test to assist in the diagnosis of sepsis 
or bacteremia.

    The Triage LBP System (consisting of the Triage LBP Assay and the Triage 
Meter) is designed to enable a physician to easily, rapidly and accurately 
measure LBP levels. The Triage LBP System is being developed to provide 
point-of-care physicians with a cost-effective diagnostic tool that will aid 
them in differentiating endotoxin-related complications from other 
inflammatory states with similar clinical symptoms. Additionally, the Triage 
LBP System may help identify patients that would benefit from treatment with 
anti-endotoxin drugs. The Company initiated clinical trials for the Triage 
LBP System in December 1998. The Company may not successfully develop or 
introduce any products based upon the XOMA licensed technology.

RESEARCH AND DEVELOPMENT

    As of December 31, 1998, the Company had 75 employees in research and 
development, 17 of which have Ph.D.s. The Company's research and development 
organization is dedicated to the discovery and development of new 
technologies which can be applied to future products and to the development 
of new products with its existing platform technologies.

    The Company has a research staff dedicated to the development and 
production of antibodies through a variety of techniques. Recombinant 
techniques are used to express proteins for use as diagnostic targets. The 
Company's staff of chemists and biochemists synthesize drug targets and 
compounds for diagnostic use and seek to perfect techniques for coupling 
these compounds to biological reagents such as antibodies or labels. The 
Company's development engineering staff is involved in the design and 
development of new diagnostic device technologies as well as the processes 
for their fabrication and interaction with biological and chemical reagents. 
The Company's product development group completes final optimization of 
assays and the Company's regulatory affairs group controls all in-house and 
external clinical studies of the Company's products and prepares applications 
to the FDA for pre-market clearance or approval.

                                      -11-

<PAGE>

MANUFACTURING

    As of December 31, 1998, the Company had 106 employees in manufacturing 
involved in reagent production, device assembly, engineering, quality 
assurance/quality control and materials management.

    Biosite maintains worldwide manufacturing rights to all current and 
future products, except for the Triage Meter for which LRE maintains the 
manufacturing rights. A key strategy of the Company is to provide high 
quality analytical results in an efficient manner. To this end, the Company 
invests in the design and development of manufacturing systems and 
technologies that can produce a high quality product using controlled, 
cost-effective manufacturing processes and equipment. The Triage C. DIFFICILE 
and Triage Parasite Panels utilize the same or similar processes and 
equipment as the Triage DOA Panel. The Company believes that the experience 
it has acquired in manufacturing the Triage DOA Panel will provide benefits 
in product quality and cost in manufacturing these new products and the 
Triage Enteric Panel under development. During 1997 and 1998, the Company 
developed the processes and systems for the manufacturing of its Triage 
Cardiac System. As a result of manufacturing scale-up and capacity constraint 
issues related to the production of the Triage Cardiac System, the Company 
developed a backlog of orders for this product during the third and fourth 
quarter of 1998. The Company addressed the manufacturing scale-up issues and 
filled the backlog orders during December 1998 and the first quarter of 1999. 
The Company expects its manufacturing capacities to be sufficient to 
concurrently manufacture these new products and the Triage DOA Panel in the 
same facility.

    Except for the Triage Meter, all of the Company's products are 
manufactured at its facility in San Diego, California. The Triage Meter is 
purchased from LRE Relais + Elektronik GmbH ("LRE"), which is located in 
Germany. Most of the antibodies used in the manufacture of the products were 
developed by Biosite and the cell lines are owned or licensed by Biosite. In 
addition, Biosite maintains its own in-house antibody production capability. 
All other raw materials required to manufacture the Company's products are 
obtained from outside suppliers.

    The San Diego facility has received its registration as a diagnostic 
product manufacturer from the FDA and from the California State Department of 
Health & Services. The Company has also been licensed and certified to 
manufacture products using controlled substances by the U.S. Drug Enforcement 
Agency. However, there can be no assurance that the Company can continue to 
comply with all government requirements and regulations that may lead to the 
suspension or revocation of its right to manufacture. See "-- Government 
Regulation" and "Risk Factors-- Government Regulation."

    The Company has also developed and continues to improve its novel and 
sophisticated processes and equipment for the production of its Triage 
Cardiac Panel. LRE manufactures and supplies the meters used in the Company's 
Triage Meter System platform products. The Company has increased its 
manufacturing space at its San Diego facility to accommodate production of 
the Triage Cardiac Panel.

SALES AND MARKETING

As of December 31, 1998, the Company has 49 employees in various sales and 
marketing functions. The Company distributes its products to hospital 
facilities in the United States primarily through Fisher, and in certain 
countries in Europe, Latin America, the Middle East, Asia and Africa through 
country-specific and regional distributors.

    The Company anticipates that it may, if appropriate, enter into 
additional distribution agreements with respect to its current products, 
products currently under development and products that it develops in the 
future, provided such products receive the requisite regulatory clearance or 
approvals. The Company may not be able to enter into these or other 
distribution agreements on acceptable terms, if at all. If the Company elects 
to distribute products directly, it's direct sales, marketing and 
distribution efforts may not be successful. A failure to enter into 
acceptable distribution agreements or a failure of the Company to 
successfully market its products would have a material and adverse effect on 
the Company.

STRATEGIC AND DISTRIBUTION ARRANGEMENTS

    Biosite's strategy for the research, development, commercialization and
distribution of some of its products entails entering into various arrangements
with corporate partners, licensors, licensees and others, and is dependent upon
the

                                      -12-

<PAGE>

success of these parties in performing their responsibilities. There can be 
no assurance that these parties will perform their obligations as expected or 
that any revenue will be derived from any of the arrangements. Under 
Biosite's existing arrangements, Biosite is not obligated to make any 
material capital expenditures. If products are successfully developed under 
certain of the Company's existing arrangements, royalties will be payable by 
the Company on sales of products which incorporate licensed technology.

FISHER HEALTHCARE DIVISION (FORMERLY CURTIN MATHESON SCIENTIFIC DIVISION) OF 
FISHER SCIENTIFIC COMPANY

    In April 1998, the Company entered into a new distribution agreement (the 
"Fisher Agreement") with Fisher which expanded Fisher's role to include the 
distribution of the Company's new products and certain potential new products 
currently under development. Under the agreement, the Company granted to 
Fisher an exclusive right to distribute Triage DOA Panel products, Triage 
Micro Panel products, and Triage Cardiac System products to hospitals and 
reference laboratories within the United States. Under certain circumstances 
in the event that the Company elects to terminate the Fisher Agreement 
without cause, the Company is obligated to make a one-time payment to Fisher. 
Fisher purchases Biosite products on a monthly basis through firm purchase 
orders. Fisher accounted for 81%, 80%, and 86% of Biosite's product sales for 
the years ended December 31, 1996, 1997 and 1998, respectively.

LRE RELAIS + ELEKTRONIK GMBH ("LRE")

    In September 1994, the Company entered into an agreement with LRE (the 
"LRE Agreement") for the development of a hand-held meter to be used in all 
Triage Meter System products commercially available or under development, 
including the Triage Cardiac System, NeoralChek System, Triage BNP System and 
Triage LBP System. Under the terms of the LRE Agreement, LRE developed and 
produced the fluorescent meter according to specifications provided by 
Biosite. For a total of approximately $1.9 million, the Company paid LRE for 
certain development and tooling expenses incurred in the development of the 
meter, based upon LRE's successful completion of certain feasibility, 
prototype and preproduction milestones. In addition, the agreement specifies 
that LRE is to be the Company's exclusive supplier of the Triage Meter during 
the term of the LRE Agreement, unless LRE is incapable of satisfying 
Biosite's needs or is prohibited from producing such meters for a specific 
immunoassay application. Biosite will purchase the Triage Meters from LRE in 
Deutsche Marks (or a successor currency to Deutsche Marks) on a quarterly 
basis through firm purchase orders on a per device price basis which varies 
according to sales volume.

 ARKRAY KDK CORPORATION ("KDK")

    In February 1995, the Company entered into a development, supply and 
distribution agreement with KDK, pursuant to which the parties agreed to 
collaborate in the development and marketing of the Triage Cardiac System. 
Under the terms of the agreement, KDK is obligated to provide funding of up 
to $2.0 million for the Company's development of the Triage Cardiac System, 
$1.8 million of which has been paid and the remainder of which is to be paid 
based upon the Company's achievement of milestones. In exchange for this 
funding, the Company has granted KDK the exclusive right to distribute the 
Triage Cardiac System in Japan and in certain countries of Asia, the Middle 
East and Pacific Island countries (the "KDK countries"). The Company was 
responsible for costs associated with performing clinical trials on and 
obtaining regulatory approval of the Triage Cardiac System in the United 
States, while KDK is responsible for such costs in Japan and in countries of 
Asia, the Middle East and Pacific Island countries. If the Triage Cardiac 
System is approved for commercial sale in the KDK countries, KDK will 
purchase Triage Cardiac Panels from Biosite in U.S. dollars on a quarterly 
basis through firm purchase orders on a per device fixed price basis. KDK 
will also purchase the Triage Meters from the Company on a per device fixed 
price basis. The distribution agreement provides for minimum annual purchase 
quantities. KDK can terminate this agreement at any time.

 NOVARTIS PHARMA AG ("NOVARTIS")

    In September 1995, the Company entered into two license agreements with
Novartis relating to the Company's development of the NeoralChek System. The
first license is for cyclosporine antibodies and the second license is for
certain antibody-based assays. Under the terms of the agreements, and upon the
Company's successful completion of certain feasibility requirements, the Company
has the right to make, have made, use and sell the NeoralChek System using the
licensed Novartis antibodies and related technologies. The agreements
contemplate that the Company is to be responsible for all costs associated with
the development of the NeoralChek System. Under the two licenses, the

                                      -13-

<PAGE>

Company made payments (aggregating approximately $361,000) to Novartis and is 
obligated to make additional payments of up to approximately $170,000 to 
Novartis based upon the achievement of certain product development 
milestones, and to pay royalties on sales of products developed by the 
Company using such antibodies or related technologies. In connection with the 
agreement, Novartis purchased $1.0 million of five-year 8% convertible 
debentures which converted into 92,575 shares of Common Stock of the Company 
upon the closing of the Company's initial public offering in February 1997. 
In January 1998, as a result of the attainment of one of the milestones (the 
successful completion of feasibility studies for the NeoralChek System under 
development), the Company received $500,000 from Novartis in exchange for a 
convertible debenture. The convertible debenture was immediately converted 
into 41,666 shares of common stock of the Company based on the conversion 
price of $12.00 per share. The Company is obligated to sell to Novartis an 
additional $500,000 five-year 8% convertible debenture upon the attainment of 
a milestone. The debenture would be convertible, at the sole option of the 
Company, into shares of Biosite Common Stock at $12.00 per share. 
Additionally, the Company and Novartis expanded the scope of their 
collaboration to include the development of a second version of the 
NeoralChek System. The attainment of certain milestones under the expansion 
of the collaboration resulted in contract revenues of $1.1 million during 
1998. Additional payments to Biosite will be made if certain milestones are 
achieved. The Company initiated clinical trials for both versions of the 
NeoralChek System in June and July 1998. The clinical trials were suspended 
in September 1998 to permit the Company to make improvements to the 
NeoralChek System. The clinical trials may resume in the first half of 1999.

PROPRIETARY TECHNOLOGY AND PATENTS

    The Company's ability to compete effectively will depend in part on its 
ability to develop and maintain proprietary aspects of its technology, and to 
operate without infringing the proprietary rights of others or to obtain 
licenses to such proprietary rights. Biosite has U.S. and foreign issued 
patents and is currently prosecuting patent applications in the United States 
and with certain foreign patent offices. There can be no assurance that any 
of the Company's pending patent applications will result in the issuance of 
any patents, that the Company's patent applications will have priority over 
others' applications, or that, if issued, any of the Company's patents will 
offer protection against competitors with similar technology. There can be no 
assurance that any patents issued to the Company will not be challenged, 
invalidated or circumvented in the future or that the rights created 
thereunder will provide a competitive advantage.

    The Triage DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel, 
Triage Cardiac System and products under development may incorporate 
technologies that are the subject of patents issued to, and patent 
applications filed by, others. The Company has obtained licenses for certain 
technologies and is negotiating to obtain licenses for technologies patented 
by others. However, there can be no assurance that the Company will be able 
to obtain licenses for technology patented by others on commercially 
reasonable terms, if at all, that it will be able to develop alternative 
approaches if it is unable to obtain licenses or that the Company's current 
and future licenses will be adequate for the operation of Biosite's business. 
The failure to obtain necessary licenses or to identify and implement 
alternative approaches would prevent the Company from commercializing certain 
of its products under development and would have a material adverse effect on 
the Company's business, financial condition and results of operations.

    Litigation may be necessary to enforce any patents issued to the Company 
to protect trade secrets or know-how owned by the Company or to determine the 
enforceability, scope and validity of the proprietary rights of others. In 
March 1996, the Company settled a potential patent infringement claim by 
obtaining a license to the contested patent in return for a one-time payment 
of $2.2 million. In September 1996, the Company settled a patent infringement 
claim filed by Abbott Laboratories and obtained a license to the contested 
patent in return for the payment of $5.5 million and the agreement to pay 
certain royalties.

    In September 1997, Behring Diagnostics, Inc. and Behring Diagnostics, 
GmbH filed a patent infringement action against the Company in the U.S. 
District Court for the District of Delaware. The patent infringement action 
alleged that the Company's Triage DOA Panel products infringed a patent held 
by the plaintiffs, which expires in August 2000. The plaintiffs sought to 
recover damages of an unspecified amount and to enjoin future sales of the 
Triage DOA Panel products by the Company. Biosite answered the complaint, 
denying infringement and asserting affirmative defenses that the patent is 
invalid and unenforceable. Because of a merger, the identity of the 
plaintiffs changed to Dade Behring Inc., Dade Behring Marburg GmbH and Syva 
Company (collectively "Dade-Behring"). To avoid protracted litigation and 
continued significant legal defense costs, the Company and Dade Behring 
executed a settlement agreement in March 1999 that resolved all disputes 
outstanding between the companies. Under the terms

                                      -14-

<PAGE>

of the settlement agreement, the Company obtained a license to the patent and 
will provide Dade-Behring the option to evaluate certain proprietary 
antibodies, resulting in a net payment of $1,050,000 to Dade-Behring by 
Biosite.

    On April 28, 1998, Spectral Diagnostics, Inc. ("Spectral") filed a patent 
infringement action against the Company in the U.S. District Court for the 
Western District of Wisconsin, alleging that the Company's Triage Cardiac 
Panel infringes U.S. patent 5,744,358 which was issued on the date the suit 
was filed. Spectral sought a permanent injunction and damages. Spectral also 
sought a preliminary injunction that would enjoin the Company from selling 
the Triage Cardiac Panel. On July 16, 1998, the Court issued an opinion 
denying the motion for a preliminary injunction. Spectral also moved for 
partial summary judgment on the issue of infringement. That motion was denied 
on July 20, 1998. The established trial date of August 31, 1998 was set aside 
while the two companies engaged in negotiations in an attempt to arrive at a 
settlement in regards to all disputes outstanding between Biosite and 
Spectral. In February 1999, a settlement agreement was executed that resolved 
all disputes between the companies without a material adverse financial 
impact to Biosite.

    The Company also has received correspondence from other parties calling 
to the Company's attention the existence of patents that they believe cover 
technology which is or may be incorporated in Biosite's products and products 
under development. Some of this correspondence has included offers to 
negotiate the licensing of the patented technologies. There can be no 
assurance that these matters will not result in litigation to determine the 
enforceability, scope, and validity of the patents. Litigation, if initiated, 
could seek to recover damages as a result of any sales of the products and to 
enjoin further sales of such products.

    Litigation that could be brought forth by other parties may result in 
material expenses to the Company and significant diversion of effort by the 
Company's technical and management personnel, regardless of the outcome. The 
outcome of litigation is inherently uncertain and there can be no assurance 
that a court would not find the third-party claims valid and that the Company 
had no successful defense to such claims. An adverse outcome in litigation or 
the failure to obtain a necessary license could subject the Company to 
significant liability and could prevent the Company from selling the Triage 
DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel or the Triage 
Cardiac System, which could have a material adverse effect on the Company's 
business, financial condition and results of operations.

    The Company also relies upon trade secrets, technical know-how and 
continuing invention to develop and maintain its competitive position. There 
can be no assurance that others will not independently develop substantially 
equivalent proprietary information and techniques or otherwise gain access to 
the Company's trade secrets or disclose such technology, or that the Company 
can meaningfully protect its trade secrets, or that the Company will be 
capable of protecting its rights to its trade secrets.

    Others may have filed and in the future are likely to file patent 
applications that are similar or identical to those of the Company. To 
determine the priority of inventions, the Company may have to participate in 
interference proceedings declared by the USPTO that could result in 
substantial cost to the Company. No assurance can be given that any patent 
application of another will not have priority over patent applications filed 
by the Company.

    The commercial success of the Company also depends in part on the Company
neither infringing patents or proprietary rights of third parties nor breaching
any licenses that may relate to the Company's technologies and products. The
Company is aware of several third-party patents that may relate to the Company's
technology. There can be no assurance that the Company does not or will not
infringe these patents, or other patents or proprietary rights of third parties.
In addition, the Company has received and may in the future receive notices
claiming infringement from third parties as well as invitations to take licenses
under third party patents. Any legal action against the Company or its
collaborative partners claiming damages and seeking to enjoin commercial
activities relating to the Company's products and processes affected by third
party rights, in addition to subjecting the Company to potential liability for
damages, may require the Company or its collaborative partner to obtain a
license in order to continue to manufacture or market the affected products and
processes. There can be no assurance that the Company or its collaborative
partners would prevail in any such action or that any license (including
licenses proposed by third parties) required under any such patent would be made
available on commercially acceptable terms, if at all. There are a significant
number of U.S. and foreign patents and patent applications in the Company's
areas of interest, and the Company believes that there may be significant
litigation in the industry regarding patent and other intellectual property
rights. If the Company becomes involved in such litigation, it could consume a
substantial portion of the Company's managerial and financial resources, which
could have a material adverse effect on the Company's

                                      -15-

<PAGE>

business, financial condition and results of operations.

COMPETITION

    The market in which the Company competes is intensely competitive. 
Biosite's competitors include health care companies that manufacture rapid 
tests, laboratory-based tests and analyzers, as well as clinical reference 
laboratories. The majority of diagnostic tests used by physicians and other 
health care providers are performed by independent clinical reference 
laboratories and hospital-based laboratories. The Company expects that these 
laboratories will compete vigorously to maintain their dominance of the 
testing market. In order to achieve market acceptance for its products, the 
Company will be required to demonstrate that its products provide 
cost-effective and time saving alternatives to tests performed by clinical 
reference laboratories or traditional hospital-based laboratory procedures. 
This will require physicians to change their established means of having 
these tests performed. The Company's products may not be able to compete with 
the testing services provided by traditional laboratory services. In 
addition, companies with a significant presence in the diagnostic market, 
such as Abbott Laboratories, Roche Boehringer Mannheim Corporation, Bayer 
Diagnostics, Ortho Clinical Diagnostics, a division of Johnson & Johnson, and 
Dade Behring, have developed or are developing diagnostic products that do or 
will compete with the Company's products. These competitors have 
substantially greater financial, technical, research and other resources and 
larger, more established marketing, sales, distribution and service 
organizations than the Company. Moreover, such competitors offer broader 
product lines and have greater name recognition than the Company, and offer 
discounts as a competitive tactic. In addition, several smaller companies are 
currently making or developing products that compete with or will compete 
with those of the Company. The Company's competitors may succeed in 
developing or marketing technologies or products that are more effective or 
commercially attractive than the Company's current or future products, or 
that would render the Company's technologies and products obsolete. Moreover, 
the Company may not have the financial resources, technical expertise or 
marketing, distribution or support capabilities to compete successfully in 
the future. In addition, competitors, many of which have made substantial 
investments in competing technologies, may be more effective than the 
Company's technologies, or may prevent, limit or interfere with the Company's 
ability to make, use or sell its products either in the United States or in 
international markets. See " -- Technology" and "-- Products and Products 
under Development."

GOVERNMENT REGULATION

    The testing, manufacture and sale of the Company's products are subject 
to regulation by numerous governmental authorities, principally the FDA and 
corresponding state and foreign regulatory agencies. Pursuant to the Federal 
Food, Drug, and Cosmetic Act, and the regulations promulgated thereunder, the 
FDA regulates the preclinical and clinical testing, manufacture, labeling, 
distribution and promotion of medical devices. The Company will not be able 
to commence marketing or commercial sales in the United States of new 
products under development until it receives clearance or approval from the 
FDA, which can be a lengthy, expensive and uncertain process. Noncompliance 
with applicable requirements can result in, among other things, fines, 
injunctions, civil penalties, recall or seizure of products, total or partial 
suspension of production, failure of the government to grant premarket 
clearance or premarket approval for devices, withdrawal of marketing 
clearances or approvals and criminal prosecution. The FDA also has the 
authority to request recall, repair, replacement or refund of the cost of any 
device manufactured or distributed by the Company.

    In the United States, medical devices are classified into one of three 
classes (i.e., Class I, II or III) on the basis of the controls deemed 
necessary by the FDA to reasonably ensure their safety and effectiveness. 
Class I devices are subject to general controls (e.g., labeling, premarket 
notification and adherence to the Quality System Regulation ("QSR") (formerly 
Good Manufacturing Practices) and Class II devices are subject to general and 
special controls (e.g., performance standards, postmarket surveillance, 
patient registries and FDA guidelines). Generally, Class III devices are 
those which must receive premarket approval by the FDA to ensure their safety 
and effectiveness (e.g., life-sustaining, life-supporting and implantable 
devices or new devices which have been found not to be substantially 
equivalent to legally marketed devices).

    Before a new device can be introduced in the market, the manufacturer must
generally obtain FDA clearance through clearance of a 510(k) notification or
approval of a pre-market approval ("PMA") application. A PMA application must be
filed if a proposed device is a new device not substantially equivalent to a
legally marketed Class I or Class II device, or if it is a preamendment Class
III device for which the FDA has called for PMAs. A PMA application must be
supported by valid scientific evidence to demonstrate the safety and
effectiveness of the device,

                                      -16-

<PAGE>

typically including the results of clinical investigations, bench tests, 
laboratory and animal studies. The PMA application must also contain a 
complete description of the device and its components and a detailed 
description of the methods, facilities and controls used to manufacture the 
device. In addition, the submission must include the proposed labeling, 
advertising literature and any training materials. The PMA approval process 
can be expensive, uncertain and lengthy, and a number of devices for which 
FDA approval has been sought by other companies have never been approved for 
marketing.

    Upon receipt of a PMA application, the FDA makes a threshold 
determination as to whether the application is sufficiently complete to 
permit a substantive review. If the FDA determines that the PMA application 
is complete, the FDA will accept the application for filing. Once the 
submission is accepted, the FDA begins an in-depth review of the PMA. The FDA 
review of a PMA application generally takes one to three years from the date 
the application is accepted, but may take significantly longer. The review 
time is often significantly extended by FDA requests for additional 
information or clarification of information already provided in the 
submission. During the review period, it is likely that an advisory 
committee, typically a panel of clinicians, will be convened to review and 
evaluate the application and provide recommendations to the FDA as to whether 
the device should be approved. The FDA is not bound by the recommendation of 
the advisory panel. Toward the end of the PMA review process, the FDA 
generally will conduct an inspection of the manufacturer's facilities to 
ensure that the facilities are in compliance with applicable QSR 
requirements. If FDA evaluations of both the PMA application and the 
manufacturing facilities are favorable, the FDA may issue either an approval 
letter or an approvable letter, which usually contains a number of conditions 
that must be met in order to secure final approval of the PMA. When and if 
those conditions have been fulfilled to the satisfaction of the FDA, the 
agency will issue a PMA approval letter, authorizing commercial marketing of 
the device for certain indications. If the FDA's evaluation of the PMA 
application or manufacturing facilities is not favorable, the FDA will deny 
approval of the PMA application or issue a non-approvable letter. The FDA may 
determine that additional clinical investigations must be performed, in which 
case the PMA may be delayed for one or more years while additional clinical 
investigations are conducted and submitted in an amendment to the PMA. 
Modifications to a device that is the subject of an approved PMA, its 
labeling or manufacturing process may require approval by the FDA of PMA 
supplements or new PMAs. Supplements to an approved PMA often require the 
submission of the same type of information required for an initial PMA, 
except that the supplement is generally limited to that information needed to 
support the proposed change from the product covered by the original PMA.

    A 510(k) clearance will be granted if the submitted information 
establishes that the proposed device is "substantially equivalent" to a 
legally marketed Class I or Class II medical device or to a preamendment 
Class III medical device for which the FDA has not called for PMAs. The FDA 
recently has been requiring more rigorous demonstration of substantial 
equivalence than in the past, including in some cases requiring submission of 
clinical data. It generally takes from three to 12 months from submission to 
obtain 510(k) premarket clearance but may take longer. The FDA may determine 
that a proposed device is not substantially equivalent to a legally marketed 
device or that additional information is needed before a substantial 
equivalence determination can be made. A "not substantially equivalent" 
determination, or a request for additional information, could prevent or 
delay the market introduction of new products that fall into this category. 
For any devices that are cleared through the 510(k) process, modifications or 
enhancements that could significantly affect safety or effectiveness, or 
constitute a major change in the intended use of the device, will require new 
510(k) submissions.

    The Company has made modifications to the Triage DOA Panel since receipt 
of initial 510(k) clearance. With respect to several of these modifications, 
the Company has filed new 510(k) notices describing the modifications, and 
has received FDA clearance of those 510(k) notices. The Company has made 
other modifications to the Triage DOA Panel which the Company believes do not 
require the submission of new 510(k) notices. There can be no assurance, 
however, that the FDA would agree with any of the Company's determinations 
not to submit a new 510(k) notice for any of these modifications, or would 
not require the Company to submit a new 510(k) notice for any of these 
modifications made to the Triage DOA Panel. If the FDA requires the Company 
to submit a new 510(k) notice for any device modification, the Company may be 
prohibited from marketing the modified the Triage DOA Panel until the 510(k) 
notice is cleared by the FDA.

    The Company is uncertain of the regulatory path to market that the FDA will
ultimately apply to the Company's products currently in development. Although
the Triage DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel and
Triage Cardiac System received 510(k) clearance, a PMA may be required for the
Triage Neoral, Triage BNP and Triage LBP Assays and other products now in
development. There can be no assurance that the FDA will not

                                      -17-

<PAGE>

determine that the Company must adhere to the more costly, lengthy and 
uncertain PMA approval process for any of the Company's products in 
development.

    There can be no assurance that the Company will be able to obtain 
necessary regulatory approvals or clearances for its products on a timely 
basis, if at all. Delays in receipt of or failure to receive such approvals 
or clearances, the loss of previously received approvals or clearances, 
limitations on intended use imposed as a condition of such approvals or 
clearances, or failure to comply with existing or future regulatory 
requirements would have a material adverse effect on the Company's business, 
financial condition and results of operations.

    Before the manufacturer of a device can submit the device for FDA 
approval or clearance, it generally must conduct a clinical investigation of 
the device. Although clinical investigations of most devices are subject to 
the investigational device exemption ("IDE") requirements, clinical 
investigations of in vitro diagnostic ("IVD") tests, such as all of the 
Company's products and products under development, are exempt from the IDE 
requirements, including the need to obtain the FDA's prior approval, provided 
the testing is noninvasive, does not require an invasive sampling procedure 
that presents a significant risk, does not intentionally introduce energy 
into the subject, and is not used as a diagnostic procedure without 
confirmation by another medically established test or procedure. In addition, 
the IVD must be labeled for research use only ("RUO") or investigational use 
only ("IUO"), and distribution controls must be established to assure that 
IVDs distributed for research or clinical investigation are used only for 
those purposes.

    The Company intends to conduct clinical investigations of its products 
under development, which will entail distributing them in the United States 
on an IUO basis. There can be no assurance that the FDA would agree that the 
Company's IUO distribution of its IVD products under development will meet 
the requirements for IDE exemption. Furthermore, failure by the Company or 
the recipients of its products under development to maintain compliance with 
the IDE exemption requirements could result in enforcement action by the FDA, 
including, among other things, the loss of the IDE exemption or the 
imposition of other restrictions on the Company's distribution of its 
products under development, which would adversely affect the Company's 
ability to conduct the clinical investigations necessary to support marketing 
clearance or approval.

    Any devices manufactured or distributed by the Company pursuant to FDA 
clearance or approvals are subject to pervasive and continuing regulation by 
FDA and certain state agencies. Manufacturers of medical devices for 
marketing in the United States are required to adhere to QSR, which includes 
testing, control, documentation, and other quality assurance requirements. 
Manufacturers must also comply with Medical Device Reporting ("MDR") 
requirements that a manufacturer report to the FDA any incident in which its 
product may have caused or contributed to a death or serious injury, or in 
which its product malfunctioned and, if the malfunction were to recur, it 
would be likely to cause or contribute to a death or serious injury. Labeling 
and promotional activities are subject to scrutiny by the FDA and, in certain 
circumstances, by the Federal Trade Commission. Current FDA enforcement 
policy prohibits the marketing of approved medical devices for unapproved 
uses.

    The Company is subject to routine inspection by the FDA and certain state 
agencies for compliance with QSR requirements, MDR requirements and other 
applicable regulations. The recently finalized QSR requirements include the 
addition of design controls that will likely increase the cost of compliance. 
Changes in existing requirements or adoption of new requirements could have a 
material adverse effect on the Company's business, financial condition and 
results of operation. There can be no assurance that the Company will not 
incur significant costs to comply with laws and regulations in the future or 
that laws and regulations will not have a material adverse effect upon the 
Company's business, financial condition and results of operations.

    The Company also is subject to numerous federal, state and local laws 
relating to such matters as safe working conditions, manufacturing practices, 
environmental protection, fire hazard control and disposal of hazardous or 
potentially hazardous substances. There can be no assurance that the Company 
will not incur significant costs to comply with laws and regulations in the 
future or that such laws or regulations will not have a material adverse 
effect upon the Company's business, financial condition and results of 
operations.

    The use of Biosite's products is also affected by the Clinical Laboratory 
Improvement Amendments of 1988 ("CLIA") and related federal and state 
regulations which provide for regulation of laboratory testing. The scope of 
these regulations includes quality control, proficiency testing, personnel 
standards and federal inspections. CLIA categorizes tests as "waived," 
"moderately complex" or "highly complex," on the basis of specific criteria. 
There can

                                      -18-

<PAGE>

be no assurance that any future amendment of CLIA or the promulgation of 
additional regulations impacting laboratory testing will not have a material 
adverse effect on the Company's ability to market its products or on its 
business, financial condition or results of operations.

EMPLOYEES

    As of December 31, 1998, Biosite employed 281 individuals. Of these, 21 
hold Ph.D.s and 19 hold other advanced degrees. None of the Company's 
employees is covered by collective bargaining agreement. The Company believes 
that it maintains good relations with its employees.

                                     -19-

<PAGE>

                                  RISK FACTORS

DEPENDENCE ON DEVELOPMENT AND INTRODUCTION OF NEW PRODUCTS FOR REVENUE GROWTH 
AND PROFITABILITY

    Except for the Triage DOA Panel, Triage C. DIFFICILE Panel, Triage 
Parasite Panel and Triage Cardiac System, all of the Company's products are 
still under development and may not be successfully developed or 
commercialized on a timely basis, or at all. If the Company is unable, for 
technological or other reasons, to complete the development, introduction or 
scale-up of manufacturing for any new product or if any new product is not 
approved for marketing or does not achieve a significant level of market 
acceptance, the Company's business, financial condition and results of 
operations would be materially and adversely affected.

    The Company believes that its revenue growth and profitability will 
substantially depend upon its ability to complete development of and 
successfully introduce these new products. In addition, the successful 
development of some of these new products will depend on the development of 
new technologies. The Company will be required to undertake time-consuming 
and costly development activities and seek regulatory approval for these new 
products. The Company may experience difficulties that could delay or prevent 
the successful development, introduction and marketing of these new products. 
Regulatory clearance or approval of any new products may not be granted by 
the U.S. Food and Drug Administration or foreign regulatory authorities on a 
timely basis, or at all, and the new products may not be successfully 
commercialized. The Company has limited resources to devote to the 
development of all its potential products and consequently a delay in the 
development of one product may delay the development of other products.

    In order to successfully commercialize any new products, the Company will 
be required to establish and maintain reliable, cost-efficient, high-volume 
manufacturing capacity and a cost effective sales force and administrative 
infrastructure and an effective product distribution system for the products. 
As a result of manufacturing scale-up and capacity constraint issues related 
to the production of the Triage Cardiac System, the Company developed a 
backlog of orders for the Triage Cardiac System during the third and fourth 
quarter of 1998. See "Business-- Products and Products Under Development," 
"--Manufacturing" and "-- Government Regulation."

LIMITED HISTORY OF PROFITABILITY; POTENTIAL QUARTERLY FLUCTUATIONS IN FUTURE 
OPERATING RESULTS

    The Company incurred an operating loss during the last five quarters. The 
Company may not return to operating profitability on a quarterly or annual 
basis in the future. The Company believes that future operating results will 
be subject to quarterly fluctuations due to a variety of factors, including 
whether and when new products are successfully developed and introduced by 
the Company, market acceptance of current or new products, regulatory delays, 
product recalls, manufacturing delays or capacity constraints, shipment 
problems, seasonal customer demand, the timing of significant orders, changes 
in reimbursement policies, competitive pressures on average selling prices, 
changes in the mix of products sold and defense and resolution of patent 
matters.

    Operating results would also be adversely affected by a downturn in the 
market for the Company's current and future products, if there are any. 
Because the Company is continuing to increase its operating expenses for 
supporting its expanded sales and marketing activities, manufacturing 
scale-up costs and new product development, the Company's operating results 
would be adversely affected if its sales and gross profits did not 
correspondingly increase or if its product development efforts are 
unsuccessful or subject to delays. The Company's limited operating history 
makes accurate prediction of future operating results difficult or 
impossible. The Company may not sustain revenue growth or remain profitable 
on a quarterly or annual basis and its growth or operating results may not be 
consistent with predictions made by securities analysts. See "Management's 
Discussion and Analysis of Financial Condition and Results of Operations."

NEAR-TERM DEPENDENCE OF THE COMPANY ON THE TRIAGE DOA PANEL

    To date, sales of the Triage DOA Panel products have accounted for almost
all of the Company's sales. The Company expects its revenue and profitability
will substantially depend on the sale of the Triage DOA Panel products for the
foreseeable future. A reduction in demand for the Triage DOA Panel products
would have a material adverse effect on the Company's business, financial
condition and results of operations. The Company believes that growth in

                                      -20-

<PAGE>

sales of the Triage DOA Panel products is slowing as the available U.S. 
market becomes saturated. Competitive pressures could also erode the 
Company's profit margins for the Triage DOA Panel products. The Company's 
continued growth will depend on its ability to successfully commercialize its 
new products (the Triage C. DIFFICILE Panel, Triage Parasite Panel and Triage 
Cardiac System) and develop and commercialize other products, and to gain 
additional acceptance of the Triage DOA Panel products in new market 
segments, such as occupational health.

    During 1998, the Company received FDA approval to market the Triage C. 
DIFFICILE Panel, Triage Parasite Panel and the Triage Cardiac System and 
began selling each of the products in March, October and May, respectively. 
Sales of these new products represented less than 7% of net sales in 1998.

    The Company may not be able to successfully develop and commercialize new 
products, including the Triage C. DIFFICILE Panel, Triage Parasite Panel, and 
Triage Cardiac System, and the Company may not be able to maintain or expand 
its share of the drug-testing market. Technological change or the development 
of new or improved diagnostic technologies could result in the Company's 
products becoming obsolete or noncompetitive. See "Business -- Products and 
Products Under Development."

DEPENDENCE ON KEY DISTRIBUTORS; LIMITED DIRECT SALES EXPERIENCE

    The Company relies upon key distributor alliances, such as with Fisher, 
to distribute the Triage DOA Panel products, Triage C. DIFFICILE Panel, 
Triage Parasite Panel and Triage Cardiac System and may rely upon 
distributors to distribute products under development. The Triage DOA Panel 
products are currently marketed pursuant to exclusive distribution agreements 
in the U.S. hospital market segment by Fisher (which accounted for 86% of 
product sales in 1998) and in some countries in Europe, Latin America, the 
Middle East, Asia and Africa by country-specific and regional distributors. 
The loss or termination of one or more of these distributors could have a 
material adverse effect on the Company's sales unless suitable alternatives 
can be arranged.

    As the Company has launched three new products in 1998 and with the 
potential launch of additional products from the Company's development 
pipeline, the Company has increased the size of its sales force in the U.S. 
and negotiated a new long-term distribution agreement with Fisher. This 
long-term distribution agreement expanded Fisher's role to include the 
distribution of the Triage Cardiac System, the Triage C. DIFFICILE Panel, 
Triage Parasite Panel and some of Biosite's potential new products in the 
U.S. medical market.

    If any of the Company's distribution or marketing agreements are 
terminated and the Company is unable to enter into alternative agreements or 
if the Company elects to distribute new products directly, the Company would 
have to invest in additional sales and marketing resources, including 
additional field sales personnel, which would significantly increase future 
selling, general and administrative expenses. The Company has limited 
experience in direct sales, marketing and distribution of its products. The 
Company's direct sales, marketing and distribution efforts may not be 
successful. Further, Biosite may not be able to enter into new distribution 
or marketing agreements on satisfactory terms, or at all. A failure to enter 
into acceptable distribution agreements or a failure of the Company to 
successfully market its products would have a material and adverse effect on 
the Company.

INTENSELY COMPETITIVE INDUSTRY; RAPID TECHNOLOGICAL CHANGE

    The market in which the Company competes is intensely competitive. 
Biosite's competitors include health care companies that manufacture rapid 
tests, laboratory-based tests and analyzers, as well as clinical reference 
laboratories. Currently, the majority of diagnostic tests used by physicians 
and other health care providers are performed by independent clinical 
reference laboratories and hospital-based laboratories. The Company expects 
that these laboratories will compete vigorously to maintain their dominance 
of the testing market. In order to achieve market acceptance for its 
products, the Company will be required to demonstrate that its products 
provide cost-effective and time saving alternatives to tests performed by 
clinical reference laboratories or traditional hospital-based laboratory 
procedures. This will require physicians to change their established means of 
having such tests performed. The Company's products may not be able to 
compete with the testing services provided by traditional laboratory services.

    In addition, companies with a significant presence in the diagnostic 
market, such as Abbott Laboratories, Roche Boehringer Mannheim Corporation, 
Bayer Diagnostics, Ortho Clinical Diagnostics, a division of Johnson & 
Johnson, and DADE Behring, have developed or are developing diagnostic 
products that do or will compete

                                      -21-

<PAGE>

with the Company's products. These competitors have substantially greater 
financial, technical, research and other resources and larger, more 
established marketing, sales, distribution and service organizations than the 
Company. Moreover, these competitors offer broader product lines and have 
greater name recognition than the Company, and offer discounts as a 
competitive tactic. In addition, several smaller companies are currently 
making or developing products that compete with or will compete with those of 
the Company. The Company's competitors may succeed in developing or marketing 
technologies or products that are more effective or commercially attractive 
than the Company's current or future products, or that would render the 
Company's technologies and products obsolete. Moreover, the Company may not 
have the financial resources, technical expertise or marketing, distribution 
or support capabilities to compete successfully in the future. In addition, 
competitors, many of which have made substantial investments in competing 
technologies, may be more effective than the Company or may prevent, limit or 
interfere with the Company's ability to make, use or sell its products either 
in the United States or in international markets. See "Business -- 
Technology," " -- Products and Products Under Development" and "-- 
Competition."

UNCERTAINTY OF PATENT AND PROPRIETARY TECHNOLOGY PROTECTION; POTENTIAL 
INABILITY TO LICENSE TECHNOLOGY FROM THIRD PARTIES

    The Company's ability to compete effectively will depend in part on its 
ability to develop and maintain proprietary aspects of its technology, and to 
operate without infringing the proprietary rights of others or to obtain 
licenses to such proprietary rights. Biosite has U.S. and foreign issued 
patents and is currently prosecuting patent applications in the United States 
and with certain foreign patent offices. The Company's pending patent 
applications may not result in the issuance of any patents. Additionally, the 
Company's patent applications may not have priority over others' 
applications, or, if issued, the Company's patents may not offer protection 
against competitors with similar technology. Any patents issued to the 
Company may be challenged, invalidated or circumvented in the future and the 
rights created thereunder may not provide a competitive advantage.

    The Triage DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel, 
Triage Cardiac System and products under development may incorporate 
technologies that are the subject of patents issued to, and patent 
applications filed by, others. The Company has obtained licenses for some 
technologies and may negotiate to obtain other licenses for technologies 
patented by others. However, the Company may not be able to obtain licenses 
for technology patented by others on commercially reasonable terms, or at 
all. The Company may not be able to develop alternative approaches if it is 
unable to obtain licenses and the Company's current and future licenses may 
not be adequate for the operation of it's business. The failure to obtain 
necessary licenses or to identify and implement alternative approaches would 
prevent the Company from commercializing certain of its products under 
development and would have a material adverse effect on the Company's 
business, financial condition and results of operations.

    Litigation may be necessary to enforce any patents issued to the Company, 
to protect trade secrets or know-how owned by the Company or to determine the 
enforceability, scope and validity of the proprietary rights of others. In 
March 1996, the Company settled a potential patent infringement claim by 
obtaining a license to the contested patent in return for a one-time payment 
of $2.2 million. In September 1996, the Company settled a patent infringement 
claim filed by Abbott Laboratories and obtained a license to the contested 
patent in return for the payment of $5.5 million and the agreement to pay 
certain royalties.

    In September 1997, Behring Diagnostics, Inc. and Behring Diagnostics, 
GmbH filed a patent infringement action against the Company in the U.S. 
District Court for the District of Delaware. The patent infringement action 
alleged that the Company's Triage DOA Panel products infringed a patent held 
by the plaintiffs, which expires in August 2000. The plaintiffs sought to 
recover damages of an unspecified amount and to enjoin future sales of the 
Triage DOA Panel products by the Company. Biosite answered the complaint, 
denying infringement and asserting affirmative defenses that the patent is 
invalid and unenforceable. Because of a merger, the identity of the 
plaintiffs changed to Dade Behring Inc., Dade Behring Marburg GmbH and Syva 
Company (collectively "Dade Behring"). To avoid protracted litigation and 
continued significant legal defense costs, the Company and Dade Behring 
executed a settlement agreement in March 1999 that resolved all disputes 
outstanding between the companies. Under the terms of the settlement 
agreement, the Company obtained a license to the patent and will provide 
Dade Behring the option to evaluate certain proprietary antibodies, resulting 
in a net payment of $1,050,000 to Dade-Behring by Biosite. The Company has 
charged to defense of patent matters in the accompanying statements of income 
the applicable license costs related to years prior to 1998.

    On April 28, 1998, Spectral Diagnostics, Inc. ("Spectral") filed a patent
infringement action against the Company in the U.S. District Court for the
Western District of Wisconsin, alleging that the Company's Triage Cardiac 
Panel

                                      -22-

<PAGE>

infringes U.S. patent 5,744,358 which was issued on the date the suit was 
filed. Spectral sought a permanent injunction and damages. Spectral also 
sought a preliminary injunction that would enjoin the Company from selling 
the Triage Cardiac Panel. On July 16, 1998, the Court issued an opinion 
denying the motion for a preliminary injunction. Spectral also moved for 
partial summary judgment on the issue of infringement. That motion was denied 
on July 20, 1998. The established trial date of August 31, 1998 was set aside 
while the two companies engaged in negotiations in an attempt to arrive at a 
settlement in regards to all disputes outstanding between Biosite and 
Spectral. In February 1999, a settlement agreement was executed that resolved 
all disputes between the companies without a material adverse financial 
impact to Biosite.

    The Company may become subject to additional patent infringement claims 
and litigation or interference proceedings conducted in the U.S. Patent and 
Trademark Office ("USPTO") to determine the priority of inventions. The 
Company also has received correspondence from other parties calling to the 
Company's attention the existence of patents that they believe cover 
technology which is or may be incorporated in Biosite's products and products 
under development. Some of this correspondence has included offers to 
negotiate the licensing of the patented technologies. There can be no 
assurance that these matters will not result in litigation to determine the 
enforceability, scope, and validity of the patents. Litigation, if initiated, 
could seek to recover damages as a result of any sales of the products and to 
enjoin further sales of such products.

    Litigation that could be brought forth by other parties may result in 
material expenses to the Company and significant diversion of effort by the 
Company's technical and management personnel, regardless of the outcome. The 
outcome of litigation is inherently uncertain and there can be no assurance 
that a court would not find the third-party claims valid and that the Company 
had no successful defense to such claims. An adverse outcome in litigation or 
the failure to obtain a necessary license could subject the Company to 
significant liability and could prevent the Company from selling the Triage 
DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel, the Triage 
Cardiac System or other products it may develop, which would have a material 
adverse effect on the Company's business, financial condition and results of 
operations.

    The Company also relies upon trade secrets, technical know-how and 
continuing invention to develop and maintain its competitive position. Others 
may independently develop substantially equivalent proprietary information 
and techniques or otherwise gain access to the Company's trade secrets or 
disclose such technology, and the Company may not be able to protect its 
trade secrets or its rights to its trade secrets.

    Others may have filed and in the future are likely to file patent 
applications that are similar or identical to those of the Company. To 
determine the priority of inventions, the Company may have to participate in 
interference proceedings declared by the USPTO that could result in 
substantial cost to the Company. Patent applications of others may have 
priority over patent applications filed by the Company.

    The commercial success of the Company also depends in part on the Company 
neither infringing patents or proprietary rights of third parties nor 
breaching any licenses that may relate to the Company's technologies and 
products. The Company is aware of several third-party patents that may relate 
to the Company's technology. There can be no assurance that the Company does 
not or will not infringe these patents, or other patents or proprietary 
rights of third parties. In addition, the Company has received and may in the 
future receive notices claiming infringement from third parties as well as 
invitations to take licenses under third party patents. Any legal action 
against the Company or its collaborative partners claiming damages and 
seeking to enjoin commercial activities relating to the Company's products 
and processes affected by third party rights, in addition to subjecting the 
Company to potential liability for damages, may require the Company or its 
collaborative partner to obtain a license in order to continue to manufacture 
or market the affected products and processes. The Company or its 
collaborative partners may not prevail in any such action and any license 
(including licenses proposed by third parties) required under any such patent 
may not be made available on commercially acceptable terms, or at all. There 
are a significant number of U.S. and foreign patents and patent applications 
in the Company's areas of interest, and the Company believes that there may 
be significant litigation in the industry regarding patent and other 
intellectual property rights. Litigation concerning patent and other 
intellectual property rights could consume a substantial portion of the 
Company's managerial and financial resources, which would have a material 
adverse effect on the Company's business, financial condition and results of 
operations.

GOVERNMENT REGULATION; NO ASSURANCE OF OBTAINING REGULATORY APPROVALS

                                      -23-
<PAGE>

    The testing, manufacture and sale of the Company's products are subject 
to regulation by numerous governmental authorities, principally the FDA and 
corresponding state and foreign regulatory agencies. Pursuant to the Federal 
Food, Drug and Cosmetic Act, and the regulations promulgated thereunder, the 
FDA regulates the preclinical and clinical testing, manufacture, labeling, 
distribution and promotion of medical devices. The Company will not be able 
to commence marketing or commercial sales in the United States of new 
products under development until it receives clearance or approval from the 
FDA, which can be a lengthy, expensive and uncertain process. Noncompliance 
with applicable requirements can result in, among other things, fines, 
injunctions, civil penalties, recall or seizure of products, total or partial 
suspension of production, failure of the government to grant premarket 
clearance or premarket approval for devices, withdrawal of marketing 
clearances or approvals, and criminal prosecution. The FDA also has the 
authority to request recall, repair, replacement or refund of the cost of any 
device manufactured or distributed by the Company.

    Any devices manufactured or distributed by the Company pursuant to FDA 
clearance or approvals are subject to pervasive and continuing regulation by 
the FDA and certain state agencies. Before a new device can be introduced in 
the market, the manufacturer must generally obtain FDA clearance of a 510(k) 
notification or FDA approval of a PMA application. The PMA approval process 
is more expensive, uncertain and lengthy than the 510(k) clearance process. 
The Company is uncertain of the regulatory path to market that the FDA will 
ultimately apply to the Company's products currently in development. Although 
the Triage DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel and 
Triage Cardiac System received 510(k) clearance, a PMA may be required for 
the NeoralChek System, the Triage BNP System and Triage LBP System now in 
development. There can be no assurance that with respect to any of the 
Company's products in development, the FDA will not determine that the 
Company must adhere to the more costly, lengthy and uncertain PMA approval 
process. Modifications to a device that is the subject of an approved PMA 
application, its labeling or manufacturing process may require approval by 
the FDA of a PMA supplement or a new PMA application. For any devices that 
are cleared through the 510(k) process, modifications or enhancements that 
could significantly affect safety or effectiveness, or constitute a major 
change in the intended use of the device, will require new 510(k) submissions.

    There can be no assurance that the Company will be able to obtain 
necessary regulatory approvals or clearances for its products on a timely 
basis, if at all, and delays in receipt of or failure to receive such 
approvals or clearances, the loss of previously received approvals or 
clearances, limitations on intended use imposed as a condition of such 
approvals or clearances, or failure to comply with existing or future 
regulatory requirements would have a material adverse effect on the Company's 
business, financial condition and results of operations.

    Before the manufacturer of a device can submit the device for FDA 
clearance or approval, it generally must conduct a clinical investigation of 
the device. Although clinical investigations of most devices are subject to 
the IDE requirements, clinical investigations of IVD tests, such as all of 
the Company's products and products under development, are exempt from the 
IDE requirements, including the need to obtain the FDA's prior approval, 
provided the testing is noninvasive, does not require an invasive sampling 
procedure that presents a significant risk, does not intentionally introduce 
energy into the subject, and is not used as a diagnostic procedure without 
confirmation by another medically established test or procedure. In addition, 
the IVD must be labeled for RUO or IUO, and distribution controls must be 
established to assure that IVDs distributed for research or clinical 
investigation are used only for those purposes.

    The Company intends to conduct clinical investigations of its products 
under development, which will entail distributing them in the United States 
on an IUO basis. There can be no assurance that the FDA would agree that the 
Company's IUO distribution of its IVD products under development will meet 
the requirements for IDE exemption. Furthermore, failure by the Company or 
the recipients of its products under development to maintain compliance with 
the IDE exemption requirements could result in enforcement action by the FDA, 
including, among other things, the loss of the IDE exemption or the 
imposition of other restrictions on the Company's distribution of its 
products under development, which would adversely affect the Company's 
ability to conduct the clinical investigations necessary to support marketing 
clearance or approval.

    Manufacturers of medical devices for marketing in the United States are
required to adhere to QSR, which includes testing, control, documentation and
other quality assurance requirements. Manufacturers must also comply with MDR
requirements that a manufacturer report to the FDA any incident in which its
product may have caused or contributed to a death or serious injury, or in which
its product malfunctioned and would be likely to cause or contribute to a death
or serious injury upon recurrence. Labeling and promotional activities are
subject to scrutiny by

                                      -24-

<PAGE>

the FDA and, in certain circumstances, by the Federal Trade Commission. 
Current FDA enforcement policy prohibits the marketing of approved medical 
devices for unapproved uses.

    The Company is subject to routine inspection by the FDA and certain state 
agencies for compliance with QSR requirements, MDR requirements and other 
applicable regulations. The recently finalized QSR requirements include the 
addition of design controls, that will likely increase the cost of 
compliance. There can be no assurance that the Company will not incur 
significant costs to comply with laws and regulations in the future or that 
such laws and regulations will not have a material adverse effect upon the 
Company's business, financial condition and results of operation.

    The use of Biosite's products is also affected by the CLIA and related 
federal and state regulations which provide for regulation of laboratory 
testing. The scope of these regulations includes quality control, proficiency 
testing, personnel standards and federal inspections. CLIA categorizes tests 
as "waived," "moderately complex" or "highly complex," on the basis of 
specific criteria. There can be no assurance that any future amendment of 
CLIA or the promulgation of additional regulations impacting laboratory 
testing would not have a material adverse effect on the Company's ability to 
market its products or on its business, financial condition and results of 
operations.

DEPENDENCE ON OTHERS FOR THE DEVELOPMENT OF NEW PRODUCTS

    Biosite's strategy for the research, development, commercialization and 
distribution of certain of its products entails entering into various 
arrangements with corporate partners, licensors, licensees and others, and is 
dependent upon the success of these parties in performing their 
responsibilities. These parties may not perform their obligations as expected 
and no revenue may be derived from these arrangements.

    Biosite has entered into agreements with, among others, Novartis and KDK 
for the development and marketing of products. The agreements are subject to 
rights of termination and may be terminated. The Company's collaborators may 
not abide by their contractual obligations and may discontinue or sell their 
current lines of business. The research for which the Company receives or 
provides funding may not lead to the development of products. The Company 
intends to enter into additional development and marketing agreements. The 
Company may not be able to enter into agreements on acceptable terms, or at 
all.

    The Company is continuing to enhance, with LRE, a hand-held point-of-care 
fluorescent meter for use in Triage Meter System products. The meter can be 
programmed to run a specific test through the use of changeable proprietary 
software which is also under further development by LRE. LRE may not develop 
the hardware or software on schedule, or at all, and new software may not be 
developed to permit the meter to be used for another Triage Meter System 
product. See "Business -- Strategic and Distribution Arrangements."

DEPENDENCE ON SOLE-SOURCE SUPPLIERS

    Key components and raw materials used in the manufacture of the Triage 
DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel and Triage 
Cardiac System are currently provided by single-source vendors. Although the 
Company believes that alternative sources for such components and raw 
materials are available, any supply interruption in a sole-sourced component 
of raw material would have a material adverse effect on the Company's ability 
to manufacture these products until a new source of supply is qualified and, 
as a result, would have a material adverse effect on the Company's business, 
financial condition and results of operations. In addition, an uncorrected 
impurity or supplier's variation in a raw material, either unknown to the 
Company or incompatible with the Company's Triage DOA Panel, Triage C. 
DIFFICILE Panel, Triage Parasite Panel and Triage Cardiac System 
manufacturing processes, could have a material adverse effect on the 
Company's ability to manufacture products. The Company has under development 
products other than the Triage DOA Panel, Triage C. DIFFICILE Panel, Triage 
Parasite Panel and Triage Cardiac System which, if developed, may require 
that the Company enter into additional supplier arrangements. The Company may 
not be able to enter into additional supplier arrangements on commercially 
reasonable terms, or at all. Failure to obtain a supplier for the manufacture 
of its future products, if any, would have a material adverse effect on the 
Company's business, financial condition and results of operations.

    The Company expects to rely upon LRE for production of the fluorescent meter
to be used in connection with its Triage Meter System platform products,
including the Triage Cardiac System and others currently under development. The
Company's dependence upon LRE for the manufacture of the meter may adversely
affect the

                                      -25-

<PAGE>

Company's profit margins, its ability to develop and manufacture products on 
a timely and competitive basis, the timing of market introductions and 
subsequent sales of products incorporating the LRE meter. See "Business 
- --Strategic and Distribution Arrangements."

LIMITED MANUFACTURING EXPERIENCE; POTENTIAL INABILITY TO SCALE-UP 
MANUFACTURING

    To be successful, the Company must manufacture its current and future 
products in compliance with regulatory requirements, in sufficient quantities 
and on a timely basis, while maintaining product quality and acceptable 
manufacturing costs. The Company has limited experience manufacturing 
products other than the Triage DOA Panel products. To achieve the level of 
production necessary for commercialization of Biosite's new products and 
products under development, the Company will need to scale-up current 
manufacturing capabilities. Significant additional work will be required for 
the scaling-up of each new Biosite product prior to commercialization, and 
this work may not be completed successfully.

    In addition, although the Company expects that some of its new products 
and products under development will share production attributes with the 
Triage DOA Panel, production of these products may require the development of 
new manufacturing technologies and expertise. These products may not be able 
to be manufactured by the Company or any other party at a cost or in 
quantities to make these products commercially viable. If the Company is 
unable to develop or contract for manufacturing capabilities on acceptable 
terms for its products under development, the Company's ability to conduct 
preclinical and clinical testing will be adversely affected, resulting in the 
delay of submission of products for regulatory clearance or approval and 
initiation of new development programs, which would have a material adverse 
effect on the Company's business, financial condition and results of 
operations.

    The Company anticipates making significant expenditures to develop high 
volume manufacturing capabilities required for each of its new products and 
products currently under development, if the products are successfully 
developed. Manufacturing and quality control problems may arise as the 
Company attempts to scale-up its manufacturing and such scale-up may not be 
achieved in a timely manner or at a commercially reasonable cost, or at all. 
As a result of manufacturing scale-up and capacity constraint issues related 
to the production of the Triage Cardiac System, the Company developed a 
backlog of orders for the Triage Cardiac System during the third and fourth 
quarter of 1998.

    The Company's manufacturing facilities and those of its contract 
manufacturers are or will be subject to periodic regulatory inspections by 
the FDA and other federal and state regulatory agencies and these facilities 
are subject to QSR requirements of the FDA. The Company or its contractors 
may not satisfy such regulatory requirements, and any failure to do so would 
have a material adverse effect on the Company's business, financial condition 
and results of operations.

UNCERTAINTY RELATING TO THIRD PARTY REIMBURSEMENT AND POTENTIAL COST CONSTRAINTS

    In the United States, health care providers that purchase the Triage DOA 
Panel and other diagnostic products, such as hospitals and physicians, 
generally rely on third party payors, principally private health insurance 
plans, federal Medicare and state Medicaid, to reimburse all or part of the 
cost of the procedure. Such third party payors can affect the pricing or the 
relative attractiveness of the Company's products by regulating the maximum 
amount of reimbursement provided by such payors for testing services. In 
addition, the tests performed by public health departments, corporate 
wellness programs and other large volume users in the drug screening market 
are generally not subject to reimbursement. Further, certain health care 
providers are moving towards a managed care system in which such providers 
contract to provide comprehensive health care for a fixed cost per patient. 
The Company is unable to predict what changes will be made in the 
reimbursement methods utilized by third party payors. The Company could be 
adversely affected by changes in reimbursement policies of governmental or 
private health care payors, particularly to the extent any such changes 
affect reimbursement for procedures in which the Company's products are used. 
Third party payors are increasingly scrutinizing and challenging the prices 
charged for medical products and services. Decreases in reimbursement amounts 
for tests performed using the Company's products may decrease amounts 
physicians and other practitioners are able to charge patients, which in turn 
may adversely affect the Company's ability to sell its products on a 
profitable basis. Failure by physicians and other users to obtain 
reimbursement from third party payors, or changes in government and private 
third party payors' policies toward reimbursement of tests utilizing the 
Company's products could have a material adverse effect on the Company's 
business, financial condition or results of operation. Given the efforts to 
control and reduce health care costs in the United States in recent years, 
there can be no assurance that currently available levels of reimbursement 
will continue

                                      -26-

<PAGE>


to be available in the future for the Company's existing products or products 
under development.

    In addition, market acceptance of the Company's products in international 
markets is dependent, in part, upon the availability of reimbursement within 
prevailing health care payment systems. Reimbursement and health care payment 
systems in international markets vary significantly by country, and include 
both government sponsored health care and private insurance.

    The Company believes that the overall escalating cost of medical products 
and services has led to and will continue to lead to increased pressures on 
the health care industry, both foreign and domestic, to reduce the cost of 
products and services, including products offered by the Company. Third party 
reimbursement and coverage may not be available or adequate in either U.S. or 
foreign markets, current reimbursement amounts may be decreased in the future 
and future legislation, regulation or reimbursement policies of third-party 
payors may adversely affect the demand for the Company's products or its 
ability to sell its products on a profitable basis.

POSSIBLE FUTURE CAPITAL REQUIREMENTS; UNCERTAINTY OF ADDITIONAL FUNDING

    The Company believes that its available cash, cash from operations and 
funds from existing credit arrangements will be sufficient to satisfy its 
funding needs for at least the next 24 months. Thereafter, if cash generated 
from operations is insufficient to satisfy the Company's working capital and 
capital expenditure requirements, the Company may be required to sell 
additional equity or debt securities or obtain additional credit facilities. 
Additional capital, if needed, may not be available on satisfactory terms, or 
at all.

    Furthermore, any additional equity financing may be dilutive to 
stockholders, and debt financing, if available, may include restrictive 
covenants. The Company's future liquidity and capital funding requirements 
will depend on numerous factors, including the extent to which the Company's 
new products and products under development are successfully developed, gain 
market acceptance and become and remain competitive, the timing and results 
of clinical studies and regulatory actions regarding the Company's potential 
products, the costs and timing of further expansion of sales, marketing and 
manufacturing activities, facilities expansion needs, and the costs and 
timing associated with the enforcement, defense and resolution of patent 
matters, including potential licensing of certain technologies patented by 
others. The failure by the Company to raise capital on acceptable terms when 
needed could have a material adverse effect on the Company's business, 
financial condition and results of operations. See "Management's Discussion 
and Analysis of Financial Condition and Results of Operations -- Liquidity 
and Capital Resources."

POTENTIAL INABILITY TO MANAGE GROWTH; DEPENDENCE ON KEY PERSONNEL

    The Company anticipates increased growth in the number of its employees, 
the scope of its operating and financial systems and the geographic area of 
its operations as new products are developed and commercialized. This growth 
will result in an increase in responsibilities for both existing and new 
management personnel. The Company's ability to manage growth effectively will 
require it to continue to implement and improve its operational, financial 
and management information systems and to train, motivate and manage its 
employees. The Company may not be able to manage its expansion, and a failure 
to do so could have a material adverse effect on the Company's business, 
financial condition and results of operations.

    The Company's future success depends in part on the continued service of 
its key technical, sales, marketing and executive personnel, and its ability 
to identify and hire additional qualified personnel. Competition for such 
personnel is intense and the Company may not be able to retain existing 
personnel or identify or hire additional personnel.

PRODUCT LIABILITY EXPOSURE; INADEQUACY OR UNAVAILABILITY OF INSURANCE COVERAGE

    The testing, manufacturing and marketing of medical diagnostic devices such
as the Triage DOA Panel, Triage C. DIFFICILE Panel, Triage Parasite Panel and
Triage Cardiac System, as well as the Company's products currently under
development, entail an inherent risk of product liability claims. To date, the
Company has not experienced any material product liability claims, but any such
claims arising in the future could have a material adverse effect on the
Company's business, financial condition and results of operations. Potential
product liability claims may exceed the amount of the Company's insurance
coverage or may be excluded from coverage under the terms of the policy. The

                                      -27-

<PAGE>

Company's existing insurance may not be renewed at a cost and level of 
coverage comparable to that presently in effect, or at all. In the event that 
the Company is held liable for a claim against which it is not indemnified or 
for damages exceeding the limits of its insurance coverage, that claim could 
have a material adverse effect on the Company's business, financial condition 
and result of operations.

IMPACT OF YEAR 2000 ISSUE

    The Y2K Issue could have a material adverse impact on the operations of 
the Company. Additionally, the systems of other companies on which Biosite's 
systems rely may not be timely converted, which may have an adverse effect on 
the Company's systems. For example, to the extent that customers would be 
unable to order products or pay invoices or suppliers would be unable to 
manufacture or deliver product, the Company's operations would be adversely 
affected.

                                      -28-

<PAGE>

ITEM 2. PROPERTIES

    The Company leases approximately 120,000 square feet of space in seven 
buildings in the Sorrento Valley area in San Diego under leases that expire 
from December 1999 through May 2003. The Company has renewal options for four 
buildings through 2000, two of the buildings through 2001 and one building 
through 2005. The Company believes these facilities are adequate for its 
current needs and that suitable additional or alternative space will be 
available in the future on commercially reasonable terms as needed. The 
Company's current facilities are used for its administrative offices, 
research and development facilities and manufacturing operations. The Company 
is negotiating with various parties for the leasing of a new campus corporate 
facility to be constructed in San Diego, which would be adequate for its 
future needs. The Company does not anticipate relocating its operations to 
the new facility prior to January 2001. Relocation to a new facility or 
leasing of additional facility space would be expected to result in an 
increase in rent upon occupancy.

ITEM 3. LEGAL PROCEEDINGS

    In September 1997, Behring Diagnostics, Inc. and Behring Diagnostics, 
GmbH filed a patent infringement action against the Company in the U.S. 
District Court for the District of Delaware. The patent infringement action 
alleged that the Company's Triage DOA Panel products infringed a patent held 
by the plaintiffs, which expires in August 2000. The plaintiffs sought to 
recover damages of an unspecified amount and to enjoin future sales of the 
Triage DOA Panel products by the Company. Biosite answered the complaint, 
denying infringement and asserting affirmative defenses that the patent is 
invalid and unenforceable. Because of a merger, the identity of the 
plaintiffs changed to Dade Behring Inc., Dade Behring Marburg GmbH and Syva 
Company (collectively "Dade Behring"). To avoid protracted litigation and 
continued significant legal defense costs, the Company and Dade-Behring 
executed a settlement agreement in March 1999 that resolved all disputes 
outstanding between the companies. Under the terms of the settlement 
agreement, the Company obtained a license to the patent and will provide 
Dade Behring the option to evaluate certain proprietary antibodies, resulting 
in a net payment of $1,050,000 to Dade Behring by Biosite.

    On April 28, 1998, Spectral Diagnostics, Inc. ("Spectral") filed a patent 
infringement action against the Company in the U.S. District Court for the 
Western District of Wisconsin, alleging that the Company's Triage Cardiac 
Panel infringes U.S. patent 5,744,358 which was issued on the date the suit 
was filed. Spectral sought a permanent injunction and damages. Spectral also 
sought a preliminary injunction that would enjoin the Company from selling 
the Triage Cardiac Panel. On July 16, 1998, the Court issued an opinion 
denying the motion for a preliminary injunction. Spectral also moved for 
partial summary judgment on the issue of infringement. That motion was denied 
on July 20, 1998. The established trial date of August 31, 1998 was set aside 
while the two companies engaged in negotiations in an attempt to arrive at a 
settlement in regards to all disputes outstanding between Biosite and 
Spectral. In February 1999, a settlement agreement was executed that resolved 
all disputes between the companies without a material adverse financial 
impact to Biosite.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         Not applicable.

                                      -29-

<PAGE>

                                     PART II

ITEM 5. MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS

    The Company's common stock is traded in the over-the-counter market on the
Nasdaq National Market (the "NNM") under the symbol "BSTE". The following tables
set forth the high and low sale prices, for the Company's common stock as
reported on the NNM for the periods.

<TABLE>
<CAPTION>
       1997                                               HIGH            LOW
       ----                                            -------------   ---------
       <S>                                             <C>             <C>
       First Quarter (commencing on
         February 11, 1997).........................   $   14.125      $    9.380
       Second Quarter...............................   $    9.750      $    7.000
       Third Quarter................................   $    9.500      $    7.000
       Fourth Quarter...............................   $   11.630      $    7.880

<CAPTION>
       1998                                               HIGH            LOW
       ----                                            -------------   ---------
       First Quarter................................   $   17.750      $    8.125
       Second Quarter...............................   $   16.313      $    9.250
       Third Quarter................................   $   11.000      $    3.563
       Fourth Quarter...............................   $   12.500      $    4.250
</TABLE>

    There were approximately 146 holders of record of common stock as of 
February 28, 1999. The Company has not paid any cash dividends to date and 
does not anticipate any being paid in the foreseeable future.

                                      -30-

<PAGE>

ITEM 6. SELECTED FINANCIAL DATA

(in thousands, except per share data)

<TABLE>
<CAPTION>
                                                                 Years Ended December 31,
                                                                 ------------------------
                                                   1994        1995         1996        1997       1998
                                                ----------  ----------   ----------  ----------  ---------
<S>                                             <C>         <C>          <C>         <C>         <C>
STATEMENT OF INCOME DATA:
Net sales....................................     $16,320     $25,147      $28,206     $31,677     $34,424
Cost of sales................................       4,416       5,649        5,983       6,926      10,513
                                                  -------     -------      -------     -------     -------
Gross profit.................................      11,904      19,498       22,223      24,751      23,911

Selling, general and administrative..........       5,960       7,134        8,623      11,549      15,469
Research and development.....................       3,836       6,553        9,268      11,662      11,167
Defense of patent matters....................         338       1,217        2,368         331       4,861
                                                  -------     -------      -------     -------     -------
Total operating expenses.....................      10,134      14,904       20,259      23,542      31,497

Income (loss) from operations................       1,770       4,594        1,964       1,209      (7,586)
Interest and other income, net...............         649       1,647        1,846       3,435       5,026
 Reacquisition of distribution rights........          --          --           --      (3,364)         --
                                                  -------     -------      -------     -------     -------
Income (loss) before benefit (provision) for
  income taxes...............................       2,419       6,241        3,810       1,280      (2,560)

Benefit (provision) for income taxes.........         (63)      1,667         (261)        (82)      1,448
                                                  -------     -------      --------    --------    -------
Net income (loss)............................     $ 2,356     $ 7,908      $ 3,549     $ 1,198     $(1,113)
                                                  -------     -------      -------     -------     --------
                                                  -------     -------      -------     -------     --------
Basic net income (loss) per share............     $  2.04     $  6.46      $  2.48     $  0.11     $ (0.09)
                                                  -------     -------      -------     -------     --------
                                                  -------     -------      -------     -------     --------
Diluted net income (loss) per share..........     $  0.24     $  0.79      $  0.34     $  0.09     $ (0.09)
                                                  -------     -------      -------     -------     --------
                                                  -------     -------      -------     -------     --------
Common and common equivalent shares used in
  computing per share amounts(1)
     -   Basic...............................       1,153       1,225        1,431      11,249      12,939
     -   Diluted.............................       9,910      10,004       10,392      13,081      12,939

<CAPTION>
                                                                             DECEMBER 31,
                                                       -----------------------------------------------------
                                                          1994      1995       1996       1997       1998
                                                       --------- ---------- ---------- ---------- ----------
BALANCE SHEET DATA:
Cash, cash equivalents and marketable securities....    $ 5,916   $ 13,979   $  9,916   $ 39,257   $ 34,229
Working capital.....................................      7,974     14,428     14,305     46,611     41,214
Total assets........................................     14,364     27,935     30,089     63,311     65,809
Long-term obligations, less current portion.........        772      2,739      3,253      3,797      4,038
Stockholders' equity................................     10,512     18,526     22,153     55,090     54,683
</TABLE>

- ----------
(1) Computed on the basis described in Note 1 of Notes to Financial Statements.

                                      -31-

<PAGE>

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND 
        RESULTS OF OPERATIONS

THE MATTERS DISCUSSED IN THIS MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
CONDITION AND RESULTS OF OPERATIONS CONTAIN FORWARD-LOOKING STATEMENTS THAT
INVOLVE RISKS AND UNCERTAINTIES. THE COMPANY'S ACTUAL RESULTS COULD DIFFER
MATERIALLY FROM THOSE DISCUSSED HERE. FACTORS THAT COULD CAUSE OR CONTRIBUTE TO
SUCH DIFFERENCES INCLUDE, BUT ARE NOT LIMITED TO, THOSE DISCUSSED IN THE
SECTIONS ENTITLED "BUSINESS" AND "RISK FACTORS," AS WELL AS THOSE DISCUSSED
ELSEWHERE IN THIS ANNUAL REPORT ON FORM 10-K. THE COMPANY DISCLAIMS, ANY INTENT
OR OBLIGATION TO UPDATE THESE FORWARD-LOOKING STATEMENTS.

OVERVIEW

    Biosite Diagnostics Incorporated (the "Company") was established in 1988. 
The Company has been primarily involved in the research, development, 
manufacturing and marketing of rapid diagnostic tests. In 1992, the Company 
began commercial sales of the Company's primary product, Triage Panel for 
Drugs of Abuse ("Triage DOA Panel"). In 1998, the Company began selling three 
additional products, the Triage C. DIFFICILE Panel, the Triage Parasite Panel 
and the Triage Cardiac System. The Company markets the products worldwide 
primarily through distributors supported by the Company's direct sales force. 
In addition to focusing its attention on commercial activities associated 
with these products, the Company continues to invest in the research and 
development of additional rapid tests to aid in the diagnosis of several 
critical diseases or conditions, including congestive heart failure and 
certain bacterial infections. The Company also is developing a diagnostic 
test to aid in the dosing of immunosuppressant drugs. The principal markets 
of the Company are hospital laboratories and emergency departments.

    The Company's sales to date have primarily been due to sales of the 
Triage DOA Panel product line. The Triage DOA Panel products are marketed 
pursuant to exclusive distribution agreements in the U.S. hospital market 
segment by Fisher (which accounted for 86% of product sales in 1998) and in 
some countries in Europe, Latin America, the Middle East, Asia and Africa by 
country-specific and regional distributors. Since the launch of the Triage 
DOA Panel in fiscal 1992, the Company experienced continued revenue 
growth from its Triage DOA Panel product line. The Company believes that the 
growth in sales of Triage DOA Panel products has slowed and may decline as 
the available U.S. market becomes saturated and competitive pressures become 
more and more prominent in a maturing market.

    During 1998, the Company received final clearance from the U.S. Food and 
Drug Administration ("FDA") to market the Triage Cardiac Panel and the Triage 
Meter (together called "Triage Cardiac System") and the Triage C. DIFFICILE 
and Triage Parasite Panels in the United States. The Company began selling 
the Triage C. difficile Panel in March and the Triage Cardiac System in May. 
Sales of the Triage Parasite Panel were initiated in mid-October.

    The Company anticipates that its results of operations may fluctuate for 
the foreseeable future due to several factors, including whether and when new 
products are successfully developed and introduced by the Company, market 
acceptance of current or new products, defense and resolution of patent 
matters, regulatory delays, product recalls, manufacturing scale-up issues, 
delays, or inefficiencies, shipment problems, seasonal customer demand, the 
timing of significant orders, changes in reimbursement policies, competitive 
pressures on average selling prices and changes in the mix of products sold.

    Operating results would also be adversely affected by a downturn in the 
market for the Company's current and future products, order cancellations or 
order rescheduling or manufacturing delays. As a result of manufacturing 
scale-up and capacity constraint issues related to the production of the 
Triage Cardiac System, the Company developed a backlog of orders for the 
Triage Cardiac System during the third and fourth quarter of 1998. The 
Company addressed the manufacturing scale-up and capacity constraint issues 
and filled the backlog orders during December 1998 and the first quarter of 
1999. The Company manufactures and ships its other products shortly after 
receipt of orders and has not developed a significant backlog for such 
products and does not anticipate it will develop a material backlog for such 
products in the future.

    Because the Company is continuing to increase its operating expenses,
primarily for personnel and activities supporting newly-introduced products and
new product development, the Company's operating results would be adversely
affected if its sales did not correspondingly increase or if its product
development efforts are unsuccessful or are subject to delays. The Company's
limited operating history makes accurate prediction of future operating

                                      -32-

<PAGE>

results difficult or impossible. The Company may not sustain revenue growth 
or return to profitability on a quarterly or annual basis and its operating 
results may not be consistent with predictions made by securities analysts.

RECENT DEVELOPMENTS

NEW PRODUCTS

    During the first quarter of 1998, the Company received final clearance 
from the U.S. Food and Drug Administration ("FDA") to market the Triage 
Cardiac Panel and the Triage Meter (together called "Triage Cardiac System") 
and the Triage C. DIFFICILE Panel in the United States. The Triage Cardiac 
System is Biosite's first product to utilize the Company's Triage Meter 
System technology and is designed to deliver precise, quantitative results in 
a rapid timeframe. The Triage Cardiac System may aid in the diagnosis of 
Acute Myocardial Infarction ("AMI") and provide physicians with an enhanced 
ability to make treatment decisions in a timely manner. Used in conjunction 
with the Triage Meter, the Triage Cardiac Panel quantitatively measures, in a 
single test device, the level of CK-MB, troponin I and myoglobin from a 
whole-blood sample. The Triage C. DIFFICILE Panel is a rapid test designed to 
identify CLOSTRIDIUM DIFFICILE, an opportunistic pathogen of the intestinal 
tract that may thrive as a result of broad spectrum antibiotic treatment. The 
Company began selling the Triage C. DIFFICILE Panel in March and the Triage 
Cardiac System in May. The Company addressed manufacturing scale-up and 
capacity constraint issues related to the production of the Triage Cardiac 
system and filled the backlog orders in December 1998 and the first quarter 
of 1999. In October 1998, the Company received final clearance from the FDA to 
market the Triage Parasite Panel, the Company's third product launched in 
1998. The Triage Parasite Panel is a rapid test designed to simultaneously 
detect three common waterborne parasites, GIARDIA LAMBLIA, CRYPTOSPORIDIUM 
PARVUM and ENTAMOEBA HISTOLYTICA/DISPAR, that can cause severe 
gastrointestinal infections. Sales of the Triage Parasite Panel were 
initiated in mid-October.

RESEARCH AND DEVELOPMENT

    In January 1998, Novartis finalized its investment of an additional 
$500,000 in Biosite in exchange for a convertible debenture as a result of 
Biosite's successful completion of the initial feasibility studies for the 
NeoralChek System (formerly the "Triage Neoral System"). The convertible 
debenture was immediately converted into 41,666 shares of common stock of the 
Company based on a conversion price of $12.00 per share. Additionally, the 
Company and Novartis expanded the scope of their collaboration to include the 
development of a second version of the NeoralChek System. The attainment of 
certain milestones under the expansion of the collaboration resulted in 
contract revenues of $1.1 million during 1998. Additional payments to Biosite 
will be made if additional milestones are achieved. The Company initiated 
clinical trials for both versions of the NeoralChek System in June and July 
1998. The clinical trials were suspended in September 1998 to permit the 
Company to make improvements to the NeoralChek System. The clinical trials 
may resume in the first half of 1999. The NeoralChek Systems are designed to 
provide a cost-effective means of measuring a patient's level of cyclosporine 
on a real-time basis in order to enable physicians to optimize the dosing of 
the therapeutic drug during the patient's visit. In December, the Company 
initiated clinical trials for the Triage BNP and Triage LBP Systems. The 
Triage BNP System may be used in the diagnosis of congestive heart failure 
and the Triage LBP System may be used in the diagnosis of sepsis or 
bacteremia.

BIOSITE DISCOVERY PROGRAM

    In March 1999, the Company introduced its Biosite Discovery program, a 
collaborative research and diagnostics development program focused on the 
identification of new protein markers for acute diseases. The Company will 
seek to use its expertise in antibody development to help pharmaceutical and 
biotechnology partners accelerate their research programs. In return, Biosite 
intends to obtain diagnostic rights to the proteins under study. Biosite will 
utilize its proprietary Omniclonal antibody development technology to develop 
high affinity antibodies for the characterization and validation of protein 
targets. Initially, Biosite will focus on disease target markers in four core 
areas: cardiovascular, cerebrovascular, infectious disease and oncology. If 
the diagnostic utility of a marker is established, it will then be assessed 
for commercialization potential, with high value markers being added to 
Biosite's product development pipeline. The Company executed its first 
collaborative agreement under the Biosite Discovery program in the 
cardiovascular area with Scios in November 1998.

                                      -33-

<PAGE>

PRODUCT DISTRIBUTION AGREEMENTS

    As the Company has launched three new products in 1998 and with the 
potential launch of additional products from the Company's development 
pipeline, the Company has increased the size of its sales force in the U.S. 
and negotiated a new long-term distribution agreement with the Fisher 
HealthCare Division ("Fisher") of the Fisher Scientific Company, the 
Company's distributor of the Triage DOA Panel products in the U.S. hospital 
market segment. This long-term distribution agreement expanded Fisher's role 
to include the distribution of the Triage Cardiac System, the Triage C. 
DIFFICILE Panel, the Triage Parasite Panel and some of the potential new 
products in the U.S. medical market.

    As a result of a decision by Merck, the Company's former distributor of 
Triage DOA in Europe, to refocus away from certain aspects of the human 
diagnostic business, the Company terminated agreements with Merck for the 
development and distribution of the Triage Cardiac System and the 
distribution of the Triage DOA Panel product line in December 1997. During 
1998, the Company expended efforts related to transitioning its product 
distribution in Europe from E. Merck to a network of regional distributors. 
The Company finalized alliances with several European partners, forming a 
network of distributors to market its products in some European countries.

    The Company anticipates that it may, if appropriate, enter into 
additional distribution agreements with respect to its current products, 
products currently under development and products that it may develop in the 
future, if any of such products receive the requisite regulatory clearance or 
approvals. A failure by any of the Company's distribution partners to 
successfully market the Company's products may require that the Company 
distribute its products on a direct basis. In such circumstances, a failure 
of the Company to successfully market its products on a direct basis would 
have a material and adverse effect on the Company.

LITIGATION

    In September 1997, Behring Diagnostics, Inc. and Behring Diagnostics, 
GmbH filed a patent infringement action against the Company in the U.S. 
District Court for the District of Delaware. The patent infringement action 
alleged that the Company's Triage DOA Panel products infringed a patent held 
by the plaintiffs, which expires in August 2000. The plaintiffs sought to 
recover damages of an unspecified amount and to enjoin future sales of the 
Triage DOA Panel products by the Company. Biosite answered the complaint, 
denying infringement and asserting affirmative defenses that the patent is 
invalid and unenforceable. Because of a merger, the identity of the 
plaintiffs changed to Dade Behring Inc., Dade Behring Marburg GmbH and Syva 
Company (collectively "Dade Behring"). To avoid protracted litigation and 
continued significant legal defense costs, the Company and Dade-Behring 
executed a settlement agreement in March 1999 that resolved all disputes 
outstanding between the companies. Under the terms of the settlement 
agreement, the Company obtained a license to the patent and will provide 
Dade Behring the option to evaluate certain proprietary antibodies, resulting 
in a net payment of $1,050,000 to Dade Behring by Biosite.

    On April 28, 1998, Spectral Diagnostics, Inc. ("Spectral") filed a patent 
infringement action against the Company in the U.S. District Court for the 
Western District of Wisconsin, alleging that the Company's Triage Cardiac 
Panel infringes U.S. patent 5,744,358 which was issued on the date the suit 
was filed. Spectral sought a permanent injunction and damages. Spectral also 
sought a preliminary injunction that would enjoin the Company from selling 
the Triage Cardiac Panel. On July 16, 1998, the Court issued an opinion 
denying the motion for a preliminary injunction. Spectral also moved for 
partial summary judgment on the issue of infringement. That motion was denied 
on July 20, 1998. The established trial date of August 31, 1998 was set aside 
while the two companies engaged in negotiations in an attempt to arrive at a 
settlement in regards to all disputes outstanding between Biosite and 
Spectral. In February 1999, a settlement agreement was executed that resolved 
all disputes between the companies without a material adverse financial 
impact to Biosite.

                                      -34-

<PAGE>

RESULTS OF OPERATIONS

         The following table sets forth operating data as a percentage of net
sales:

<TABLE>
<CAPTION>
                                                                          YEAR ENDED DECEMBER 31,
                                                                          -----------------------
                                                                        1996        1997        1998
                                                                    ----------- ----------- -----------
                <S>                                                 <C>         <C>
                Net sales.....................................         100%         100%        100%
                Cost of sales.................................          21           22          31
                                                                       ---          ---         ---
                Gross profit..................................          79           78          69
                Operating expenses:
                  Selling, general and administrative.........          31           36          45
                  Research and development....................          33           37          32
                  Defense of patent matters...................           8            1          14
                                                                       ---          ---         ---
                    Total operating expenses..................          72           74          91
                Income  from operations.......................           7            4         (22)
                Other income, net.............................           7           11          15
                Reacquisition of distribution rights..........          --          (11)         --
                                                                       ---          ----        ---
                Income before benefit (provision) for income
                  taxes.......................................          14            4          (7)
                Benefit (provision) for income taxes..........          (1)          --           4
                                                                       ----         ---         ---
                Net income ...................................         13%          4%          (3)%
                                                                       ---          ---         ----
                                                                       ---          ---         ----
</TABLE>

YEARS ENDED DECEMBER 31, 1998 AND 1997

    NET SALES. Net sales increased 9% to $34.4 million in 1998 from $31.7 
million in 1997. The increase was primarily attributable to the introduction 
of new products in 1998 and the continued market acceptance of the Company's 
higher-priced Triage DOA Plus TCA Panel products. The Triage C. DIFFICILE 
Panel and Triage Parasite Panel were launched in March and October, 
respectively. The Triage Cardiac system was introduced in May. Net sales for 
the products introduced in 1998 totaled approximately $2.3 million. The 
Company believes that the growth in sales of the Triage DOA Panel products 
has slowed and may begin to decline as the available U.S. market becomes 
saturated and competitive pressures become more prominent in a maturing 
market.

    GROSS PROFIT. Gross profit decreased 3% to $23.9 million in 1998 
primarily as a result of experiencing negative gross profits related to the 
new products introduced in 1998. The overall gross margin decreased to 69% 
for 1998 from 78% for 1997. The gross margins decreased during the year 
primarily as a result of the introduction of the Triage C. DIFFICILE and 
Parasite Panels and Triage Cardiac System. During 1998, the Company 
experienced manufacturing scale-up and capacity constraint issues related to 
the Triage Cardiac System that resulted in a backlog of orders during the 
fourth quarter. The new products are expected to realize lower or negative 
gross margins during the early stages of their commercialization as 
incremental manufacturing costs are spread over smaller sales volumes and 
manufacturing scale-up, capacity constraint, and efficiency issues are 
addressed. The Company also expects that the overall gross margins will 
continue to decrease as a result of competitive pricing pressures related to 
the maturing Triage DOA product line and the incremental manufacturing costs 
associated with new products until economies of scale can be achieved with 
such new products and until other manufacturing scale-up issues are addressed.

    SELLING, GENERAL AND ADMINISTRATIVE EXPENSES. Selling, general and 
administrative expenses increased 34% to $15.5 million in 1998 from $11.5 
million in 1997. The 1998 increases resulted primarily from the cost of the 
Company's expanded sales force, increased marketing activities associated 
with new products and potential new products, and the expansion of 
administrative functions to support the Company's expanded operations and 
business development activities. Additionally, the Company expended efforts 
related to transitioning its product distribution in Europe from E. Merck to 
a network of regional distributors.

    RESEARCH AND DEVELOPMENT EXPENSES. Research and development expenses
decreased 4% to $11.2 million in 1998 from $11.7 million in 1997. Although
manufacturing scale-up and optimization expenses were significantly higher in
1998 than 1997, the timing of clinical trials and other product development
expenses in 1997 resulted in an

                                      -35-

<PAGE>

overall decrease in 1998 research and development expenses as compared to 
1997. There were significant product development activities associated with 
the Triage Cardiac System in the fourth quarter of 1997. The Company expects 
that its research and development expenses will increase in 1999, as compared 
to 1998 levels. The increased expenditures are expected to primarily relate 
to preclinical and clinical studies, product development efforts, the Biosite 
Discovery program and manufacturing scale-up activities. The Company 
initiated clinical trials for its Triage BNP System and Triage LBP System in 
late December and expects such clinical trials to extend through the first 
half of 1999 and the cost associated with such clinical trials is expected to 
be significant. These potential products are subject to more complex 
regulatory approval requirements than the Company's previous products. The 
Company also may resume clinical trials for its NeoralChek System during the 
first half of 1999. The timing of the increased expenditures and their 
magnitude are primarily dependent on the progress and success of the research 
and development and the timing of potential product launches.

    DEFENSE OF PATENT MATTERS. In 1998, the Company recorded a charge of 
approximately $4.9 million associated with the defense and settlement of two 
separate patent litigations. Settlement agreements were executed during the 
first quarter of 1999 that resolved both matters. In February 1999, a 
settlement agreement was executed that resolved all disputes between Spectral 
Diagnostics and the Company without a material adverse financial impact to 
Biosite. In March 1999, to avoid protracted litigation and continued 
significant legal defense costs, the Company and Dade-Behring executed a 
settlement agreement that resolved all disputes outstanding between the 
companies. Under the terms of this settlement agreement, the Company obtained 
a license to the patent and provided Dade-Behring the option to evaluate 
certain proprietary antibodies, resulting in a net payment of $1,050,000 to 
Dade-Behring by Biosite. The Company has charged to defense of patent matters 
in the accompanying statements of income the applicable license costs related 
to years prior to 1998 of $604,000.

    OTHER INCOME. Contract revenue increased $1.4 million in 1998 from $1.2 
million to $2.6 million. In 1998, the Company recognized $1.3 million from 
Kyoto Dai-Ichi Kagaku Co., Ltd. ("KDK") related to milestones achieved in the 
development of the Triage Cardiac System, $1.1 million from Novartis related 
to milestones achieved in the development of the NeoralChek System and 
$192,000 related to an SBIR (Small Business Innovation Research) grant from 
the U.S. Government for research related to potential microbiology products. 
In 1997, the Company recognized $778,000 from Merck related to the 
development of the Triage Cardiac System and $400,000 related to milestones 
in the development of the NeoralChek System.

    BENEFIT (PROVISION) FOR INCOME TAXES. As a result of the pre-tax loss 
recorded for 1998 and the estimated tax credits generated in 1998, the 
Company recorded a benefit for income taxes of $1.4 million. As of December 
31, 1998, the Company had federal research and development, California 
research and development, and California manufacturers' credit carryforwards 
of approximately $1,552,000, $685,000 and $425,000, respectively. The federal 
research and development, California research and development, and California 
manufacturers' credit will begin expiring in 2003, 2003, and 2005, 
respectively, unless previously utilized. As of December 31, 1998, the 
Company has approximately $4.0 million of net deferred tax assets, with no 
offsetting valuation allowance as realization of such assets has been 
assessed by the Company as more likely than not. The realization of the 
deferred tax assets is dependent upon the generation of future taxable income 
of approximately $10 million. The Company will continue to assess the 
likelihood of realization of such assets; however, if future events occur 
which do not make the realization of such assets more likely than not, the 
Company will record a valuation allowance against all or a portion of the net 
deferred tax assets.

YEARS ENDED DECEMBER 31, 1997 AND 1996

    NET SALES. Net sales increased 12% to $31.7 million in 1997 from $28.2 
million in 1996. The increase is primarily attributable to the continued 
market acceptance of the Company's Triage DOA Plus TCA Panel and Triage 
ExpressTest Panel products.

    GROSS PROFIT. Gross profit increased 11% to $24.8 million in 1997 as a 
result of increased sales of the Triage DOA Panel product line. Gross margins 
decreased slightly to 78% from 79% for 1996.

    RESEARCH AND DEVELOPMENT EXPENSES. Research and development expenses 
increased 26% to $11.7 million in 1997 from $9.3 million in 1996. This 
increase resulted primarily from the expansion of the Company's research and 
development and manufacturing scale-up efforts on its cardiac, microbiology, 
and therapeutic drug monitoring assays under development. During 1997, the 
Company continued to expend significant efforts on activities related to the

                                      -36-

<PAGE>

Triage Cardiac Panel and the Triage C. DIFFICILE Panel, while continuing 
research and development activities related to other products under 
development and other potential product launches.

    SELLING, GENERAL AND ADMINISTRATIVE EXPENSES. Selling, general and 
administrative expenses increased 34% to $11.5 million in 1997 from $8.6 
million in 1996. The 1997 increases were primarily a result of the costs of 
expanding the Company's in-house marketing and administrative functions to 
support the Company's expanded operations and public reporting 
responsibilities. During 1997, the Company continued to implement certain 
marketing programs designed to spur greater sales of its Triage DOA Panel 
products in the workplace testing market and secure long-term commitments 
from customers in the clinical market. Additionally, preparatory marketing 
activities related to the potential launch of new products were initiated.

    DEFENSE OF PATENT MATTERS. In 1997, the Company recorded legal costs 
associated with the Dade Behring litigation and other patent disputes 
totaling approximately $331,000 relating to the defense of such patent 
matters.

    OTHER INCOME. Interest income increased $1.4 million to $2.1 million in 
1997 from $736,000 in 1996. The increases resulted primarily from the higher 
average balances of cash, cash equivalents and marketable securities during 
1997 as compared to 1996. In February 1997, the Company received net proceeds 
from its initial public offering of approximately $29.8 million.

    REACQUISITION OF DISTRIBUTION RIGHTS. In 1994, the Company entered into 
an agreement with Merck to distribute the Triage Cardiac System in certain 
countries in Europe and Latin America and in South Africa. In 1996, Merck 
decided to refocus away from certain aspects of the human diagnostics 
business. In December 1997, Biosite terminated the development and 
distribution agreement with Merck for the Triage Cardiac System, paid Merck 
$2.1 million cash and forgave $1.3 million owed to the Company by Merck 
related to the development of the Triage Cardiac Panel and the Triage Meter.

    BENEFIT (PROVISION) FOR INCOME TAXES. The Company's provision for income 
taxes decreased to $82,000 in 1997 from $261,000 in 1996. In 1997, the 
Company utilized federal research and development credit carryforwards of 
approximately $98,000 to offset taxable income.

LIQUIDITY AND CAPITAL RESOURCES

    The Company has historically financed its operations through revenues 
from operations, private and public placements of equity securities, debt and 
capital lease financing and interest income earned on the net proceeds from 
the private placements. Since its inception, the Company has raised over 
$21.7 million in net cash proceeds from the private placement of equity 
securities and $1.5 million from the issuance of convertible debentures. In 
February 1997, the Company raised approximately $29.8 million in net cash 
proceeds from its initial public offering of common stock.

    During the year ended December 31, 1998, the Company generated $674,000 
in cash from operating activities despite significant investment of cash into 
its defense of patent matters and new product launch activities such as 
manufacturing scale-up tasks, inventory buildup for new products and sales 
and marketing activities. Other significant business activities affecting 
cash included the purchase of certain license rights to patented technologies 
totaling $3.9 million, the expenditure of $3.1 million for capital equipment 
and leasehold improvements, the receipt of $2.0 million in proceeds from 
equipment financing and payments under equipment financing agreements of $1.5 
million.

    During the year ended December 31, 1997, the Company generated $1.1 
million in cash from operating activities despite significant investment of 
cash into potential product launch activities such as manufacturing scale-up 
tasks and preparatory marketing activities. Net proceeds from the initial 
public offering of $29.8 million were invested primarily in marketable 
securities and have been used to fund operating activities, purchase capital 
equipment and leasehold improvements and payment of long-term obligations. 
Other significant business activities affecting cash included the $2.1 
million contract termination fee paid to Merck, the expenditure of $5.2 
million for capital equipment and leasehold improvements, the receipt of $3.1 
million in proceeds from equipment financing and payments under equipment 
financing agreements of $1.2 million.

    During the year ended December 31, 1996, the Company generated $2.4 million
in cash from operating activities.

                                      -37-

<PAGE>

Cash generated from net sales was reduced primarily by the payment of $2.2 
million for a license right accrued as of December 31, 1995 and the payment 
of $2.0 million to settle patent litigation with Abbott Laboratories. Cash 
generated from operating activities was offset by cash used in investing 
activities, primarily the acquisition of license rights from Abbott 
Laboratories for $3.5 million. Additionally, other significant business 
activities affecting cash included the generation of $3.4 million in cash as 
a result of maturing marketable securities which were not reinvested, the 
expenditure of $2.0 million for capital equipment and leasehold improvements, 
the receipt of $1.6 million in proceeds from equipment financing and payments 
under equipment financing agreements of $1.2 million.

    The Company's primary short-term needs for capital, which are subject to 
change, are for the support of its commercialization efforts related to new 
products, defense and resolution of patent matters including potential 
licensing of certain technologies patented by others, potential procurement 
and enforcement of patents, expansion of its manufacturing capacity for new 
products, potential repurchase of the Company's common stock and the 
continued advancement of research and development efforts. The Company 
executed agreements to license technologies patented by others which call for 
cash payments and future royalties based on product sales utilizing the 
licensed technologies. The Company may enter into additional licensing 
agreements which may include cash payments and future royalties based on 
product sales utilizing the licensed technologies. The Company utilizes 
credit arrangements with financial institutions to finance the purchase of 
capital equipment. As of December 31, 1998, the Company had equipment 
financing lines of credit with financial institutions totaling $6.0 million, 
of which $4.7 million was available for future borrowing. The $4.0 million 
and $2.0 million lines of credit expire on June 30, 1999 and March 31, 1999, 
respectively. Additionally, the Company utilizes cash generated from 
operating activities to meet its capital requirements.

    The Company is evaluating various alternatives in addressing its future 
facilities expansion needs. The alternatives being evaluated include 
negotiations with various parties for the leasing of additional facility 
space and potentially a new campus corporate facility to be constructed in 
San Diego, which would be adequate for its foreseeable future needs. If a new 
campus corporate facility is constructed to meet future needs, the Company 
would not anticipate relocating its operations to the new facility prior to 
January 2001. Relocation to a new facility or leasing of additional facility 
space would be expected to result in an increase in rent upon occupancy.

    The Company believes that its available cash, cash from operations and 
funds from existing credit arrangements will be sufficient to satisfy its 
funding needs for at least the next 24 months. Thereafter, if cash generated 
from operations is insufficient to satisfy the Company's working capital and 
capital expenditure requirements, the Company may be required to sell 
additional equity or debt securities or obtain additional credit facilities. 
There can be no assurance that such additional capital, if needed, will be 
available on satisfactory terms, if at all. Furthermore, any additional 
equity financing may be dilutive to stockholders, and debt financing, if 
available, may include restrictive covenants. The Company's future liquidity 
and capital funding requirements will depend on numerous factors, including 
the extent to which the Company's new products and products under development 
are successfully developed, gain market acceptance and become and remain 
competitive, the timing and results of clinical studies and regulatory 
actions regarding the Company's potential products, the costs and timing of 
further expansion of sales, marketing and manufacturing activities, 
facilities expansion needs, and the costs and timing associated with the 
enforcement, defense and resolution of patent matters, including potential 
licensing of certain technologies patented by others. The failure by the 
Company to raise capital on acceptable terms when needed could have a 
material adverse effect on the Company's business, financial condition and 
results of operations.

IMPACT OF YEAR 2000 ("Y2K") ISSUE

    The Company is implementing a plan to ensure its system, software and 
facilities infrastructure will function properly with respect to dates in the 
year 2000 and thereafter. Key financial, information and operational systems 
have been assessed and approximately 90% of them have been verified as being 
compliant. The Company is on schedule to have all remaining systems verified 
as compliant by June 30, 1999. All key suppliers, distributors, financial 
institutions and others with whom it does business have been contacted by the 
Company to assess their Y2K readiness, and approximately 60% have stated that 
they are compliant or will be compliant before December 31, 1999. The Company 
is continuing to communicate with key suppliers, distributors, financial 
institutions and others and believes that their readiness will not pose 
significant operational problems for the Company, nor have a material adverse 
effect on the Company's business. To date the Company has expended less than 
$35,000 addressing the Y2K Issue and estimates the total cost of the project 
and contingency plans, if necessary, to be under $50,000. The

                                      -38-

<PAGE>

Company anticipates that the Company will be in compliance with Y2K 
requirements by the end of June 1999.

    However, if such modifications and conversions are not made or are not 
completed in a timely fashion, the Y2K Issue could have a material adverse 
impact on the operations of the Company. Additionally, the systems of other 
companies on which Biosite's systems rely may not be timely converted, which 
may have an adverse effect on the Company's systems. The most likely worst 
case scenario is that customers would be unable to order products or pay 
invoices or suppliers would be unable to manufacture or deliver product. This 
would result in reduced orders of products and the inability of the Company 
to manufacture product.

    The Company currently does not have contingency plans in the event it 
does not complete all phases of the Y2K program. However, management is 
considering contingency plans which involve, among other actions, manual 
workarounds, increasing inventories of key components to the manufacturing 
process and validating alternate vendors. The Company plans to evaluate the 
status of the contingency plans by June 1999 and determine whether such plans 
are necessary.

The Triage Meter and related software is the only product that the Company 
currently sells which needs evaluation for Y2K readiness, as the other 
products do not process or store any date and time data. The Triage Meter and 
related software has been tested and shown to properly process and store date 
and time data between the 20th and 21st centuries, and the years 1999 and 
2000. This processing and storage included calculating, comparing, displaying 
and recording sequence operations involving date and time data. Correct 
processing of the leap year date and time data has also been demonstrated. 
The software functions as intended or expected, regardless of the date.

ITEM 7a. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

    The Company is exposed to changes in interest rates, primarily from its 
variable-rate long-term debt arrangements and, to a lesser extent, its 
investments in certain available-for-sale marketable securities. Under its 
current policies, the Company does not use interest rate derivatives 
instruments to manage this exposure to interest rate changes. The Company 
does have the option to convert its variable-rate long-term debt arrangements 
to fixed-rate debt arrangements for a nominal transaction fee. At December 
31, 1998, the Company had variable-rate debt totaling $2,046,000. A 
hypothetical 1% adverse move in interest rates along the entire interest rate 
yield curve would not materially effect the fair value of the Company's 
financial instruments that are exposed to changes in interest rates.

    Additionally, the Company's purchases of Triage Meters from LRE are 
denominated in German Deutch Marks (DM) and sales of certain products to some 
international customers are denominated in the local currency of customers. 
The Company has on occasion purchased forward exchange contracts to manage 
this exposure to exchange rate changes. As of December 31, 1998, the Company 
had no outstanding forward exchange contracts. Total receivables and payables 
denominated in foreign currencies at December 31, 1998 were not material.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

    Refer to the Index on Page F-l of the Financial Report included herein.

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND 
        FINANCIAL DISCLOSURE 

    None.

                                      -39-

<PAGE>

                                    PART III

    Some information required by Part III is incorporated by reference from 
the Company's definitive Proxy Statement to be filed with the Securities and 
Exchange Commission in connection with the solicitation of proxies for the 
Company's 1999 Annual Meeting of Stockholders (the "Proxy Statement").

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

    The information required by this section with respect to Directors is 
incorporated by reference from the information in the section entitled 
"Election of Directors" in the Proxy Statement. The executive officers of the 
Company, their positions with the Company and ages as of March 31, 1999 are 
as follows:

<TABLE>
<CAPTION>
                        NAME                     AGE                      POSITION
              --------------------------         ---  ----------------------------------------------
              <S>                                <C>  <C>
              Kim D. Blickenstaff                46   President, Chief Executive Officer, Treasurer,
                                                         Secretary and Director
              Thomas M. Watlington               43   Senior Vice President, Commercial Operations
              Kenneth F. Buechler, Ph.D.         45   Vice President, Research
              Christopher R. Hibberd             33   Vice President, Business Development
              Charles W. Patrick                 44   Vice President, Sales
              Christopher J. Twomey              39   Vice President, Finance and Chief Financial
                                                         Officer
              Gunars E. Valkirs, Ph.D.           47   Vice President, Research and Development,
                                                      Chief Technical Officer and Director
</TABLE>

    KIM D. BLICKENSTAFF, a founder of the Company, has been President and 
Chief Executive Officer since April 1988. Mr. Blickenstaff also is a director 
of Micro Therapeutics Incorporated, Amira Medical and Medi Spectra Inc. Prior 
to joining Biosite, he held various positions in finance, operations, 
research management, sales management, strategic planning, and marketing with 
Baxter Travenol, National Health Laboratories, and Hybritech Incorporated 
("Hybritech"). Mr. Blickenstaff holds an M.B.A. from the Graduate School of 
Business, Loyola University, Chicago.

    THOMAS M. WATLINGTON joined the Company as Senior Vice President in 
December 1996. He was formerly Vice President, Marketing for the Diabetes 
Care Division for Boehringer Mannheim. From 1982 to December 1996, Mr. 
Watlington held various positions in marketing, strategic analysis and 
product development with Boehringer Mannheim. Mr. Watlington holds a B.S. 
degree from the University of Maryland.

    KENNETH F. BUECHLER, PH.D., a founder of Biosite and a co-inventor of 
certain of Biosite's proprietary technology, has been Vice President, 
Research since January 1994. From April 1988 to January 1994, he was Director 
of Chemistry. Prior to forming Biosite, he was a Senior Scientist in the 
Diagnostics Research and Development Group at Hybritech. Dr. Buechler holds a 
Ph.D. in Biochemistry from Indiana University.

    CHRISTOPHER R. HIBBERD joined the Company in June 1997 to head the 
Company's business development activities after spending five years with the 
Boston Consulting Group ("BCG"). At BCG, Mr. Hibberd was a Manager, leading 
client case teams in developing and implementing value-creating strategies 
for businesses in a variety of industry sectors. Prior to that, he held 
consulting positions at various companies and also was a Development Engineer 
for Albright & Wilson Americas from 1987 to 1990. Mr. Hibberd received an 
Engineering degree from the University of Toronto, Canada and his M.B.A. from 
the University of Western Ontario, Canada.

    CHARLES W. PATRICK joined the Company in August 1990 as Vice President, 
Sales and Marketing. From 1978 to August 1990, Mr. Patrick held various 
positions in sales, sales management and product and marketing management 
with Abbott Laboratories. From 1987 to August 1990, he was Group Marketing 
Manager for the Abused Drug Business Unit of Abbott, where he managed the 
worldwide product launch of Abbott's TDx and ADx bench top testing systems. 
Mr. Patrick holds a B.A. from the University of Central Florida.

                                      -40-

<PAGE>

    CHRISTOPHER J. TWOMEY joined the Company as Director of Finance in March 
1990 and was promoted to Vice President of Finance and Chief Financial 
Officer in 1993. From 1981 to March 1990, Mr. Twomey was employed at Ernst & 
Young LLP, where from October 1985 to March 1990, he served as an Audit 
Manager. Mr. Twomey holds a B.A. in Business Economics from the University of 
California at Santa Barbara.

    GUNARS E. VALKIRS, PH.D., a founder of Biosite and a co-inventor of 
certain of its proprietary technology has been a director, Vice President, 
Research and Development and Chief Technical Officer since 1988. Prior to 
forming Biosite, he was a Scientific Investigator with the Diagnostics 
Research & Development Group at Hybritech, where he was the primary inventor 
of Hybritech's patented ICON technology. Dr. Valkirs holds a Ph.D. in Physics 
from the University of California at San Diego.

    Item 405 of Regulation S-K calls for disclosure of any known late filing 
or failure by an insider to file a report required by Section 16 of the 
Exchange Act. This disclosure is contained in the section entitled "Section 
16(a) Beneficial Ownership Reporting Compliance" in the Proxy Statement and 
is incorporated herein by reference.

ITEM 11. EXECUTIVE COMPENSATION

    The information required by this item is incorporated by reference from the
information in the section entitled "Compensation of Executive Officers and
Directors" in the Proxy Statement.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

    The information required by this item is incorporated by reference from 
the information in the section entitled "Stock Ownership of Management and 
Certain Beneficial Owners" in the Proxy Statement.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

    The information required by this item is incorporated by reference from 
the information in the section entitled "Certain Relationship and Related 
Transactions" in the Proxy Statement.

                                      -41-

<PAGE>

                                     PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

(a)   (1)  FINANCIAL STATEMENTS

    The financial statements of the Company are included herein as required
under Item 8 of this annual report on Form 10-K. See Index on page F-l.

      (2)  FINANCIAL STATEMENT SCHEDULES

    Schedule II Valuation and Qualifying Accounts

    The other financial statement schedules have been omitted since they are
either not required, not applicable, or the information is otherwise included.

      (3)  EXHIBITS

    The exhibits listed below are required by Item 601 of Regulation S-K. Each
management contract or compensatory plan or arrangement required to be filed as
an exhibit to this Form 10-K has been identified.

<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                 DESCRIPTION OF DOCUMENT
 -------                 -----------------------
<S>                      <C>
   3.(i)(1)              Restated Certificate of Incorporation, as filed with
                         the Delaware Secretary of State on February 18, 1997.

   3.(i)(4)              Certificate of Designation, as filed with the Delaware
                         Secretary of State on October 23, 1997.

  3.(ii)(2)              Amended and Restated Bylaws of the Company.

       4.1               Form of Common Stock Certificate with rights legend.

 10.1(2)(A)              Amended and Restated 1989 Stock Plan of Biosite
                         Diagnostics Incorporated.

 10.2(5)(A)              Amended and Restated 1996 Stock Incentive Plan of 
                         Biosite Diagnostics Incorporated ("1996 Stock Plan").

 10.3(2)(A)              Form of Incentive Stock Option Agreement under the 1996
                         Stock Plan.

 10.4(2)(A)              Form of Nonstatutory Stock Option Agreement under the
                         1996 Stock Plan.

    10.5(6)              Biosite Diagnostics Incorporated Employee Stock
                         Purchase Plan.

 10.6(2)(A)              Form of Indemnity Agreement between the Company and
                         its officers and directors.

    10.7(2)              Sublease Agreement between the Company and General
                         Atomics, dated February 17, 1992, as amended on August
                         10, 1992, January 21, 1993, October 29, 1993, March 1,
                         1995 and October 1, 1996.

                                      -42-

<PAGE>

  10.8(2)(+)             Antibody License Agreement between the Company and
                         Sandoz Pharma Ltd. (currently known as Novartis Pharma
                         AG), dated September 22, 1995, as amended on July 26,
                         1996.

  10.9(2)(+)             Easy Assay License Agreement between the Company and
                         Sandoz Pharma Ltd. (currently known as Novartis Pharma
                         AG), dated September 22, 1995.

 10.11(2)(+)             Development, Supply and Distribution Agreement between
                         the Company and Kyoto Dai-Ichi Kagaku Co., Ltd., dated
                         as of February 14, 1995.

 10.12(2)(+)             Development and Supply Agreement between the Company
                         and LRE Relais + Elektronik GmbH -- Medical Technology,
                         dated September 23, 1994.

    10.19(2)             Debenture Purchase Agreement between the Company and
                         Sandoz Pharma Ltd. (currently known as Novartis Pharma
                         AG), dated as of September 22, 1995.

 10.20(2)(+)             Settlement and License Agreement & Agreement of
                         Dismissal with Prejudice, between the Company and
                         Abbott Laboratories, dated as of September 6, 1996.

    10.21(2)             Lease Agreement between the Company and TCEP II
                         Properties Limited Partnership dated July 26, 1996.

    10.22(2)             Lease Agreement between the Company and Sorrento West
                         Limited dated September 21, 1994

    10.24(4)             Rights Agreement dated as of October 22, 1997 between
                         the Company and BankBoston, N.A.

10.25(7)(++)             Letter Agreement between the Company and Novartis
                         Pharma AG, dated November 20, 1997.

10.28(8)(++)             Distributorship Agreement between the Company and
                         Fisher Scientific Company L.L.C. dated April 3, 1998.

      23.1               Consent of Ernst & Young LLP, independent auditors.

      27.1               Financial Data Schedule for year ended December 31,
                         1998

      27.2               Restated Financial Data Schedule for year ended
                         December 31, 1996

      27.3               Restated Financial Data Schedule for quarters ended
                         March 31, June 30, and September 30, 1997
</TABLE>
- ----------

(1)        Incorporated by reference to Exhibit 3.(i)3 to the Company's Annual
           Report on Form 10-K for the fiscal year ended December 31, 1996.

(2)        Incorporated by reference to the exhibits of the same number to the
           Company's Registration Statement on Form S-1, No. 333-17657.

                                      -43-

<PAGE>

(3)        Incorporated by reference to Exhibit 16.23 to the Company's Quarterly
           Report on Form 10-Q for the quarter ended June 30, 1997.

(4)        Incorporated by reference to Exhibit 4.1 to the Company's
           Registration Statement of Form 8-A, filed on October 28, 1997

(5)        Incorporated by reference to Exhibit A to the Company's Definitive 
           Proxy Statement dated April 16, 1998 and filed with the Securities
           and Exchange Commission.

(6)        Incorporated by reference to Exhibit 10.2 to the Company's 
           Quarterly Report on Form 10-Q for the quarter ended June 30, 1998.

(7)        Incorporated by reference to Exhibit 10.25 to the Company's Annual 
           Report on Form 10-K for the year ended December 31, 1997.

(8)        Incorporated by reference to Exhibit 10.28 to the Company's 
           Quarterly Report on Form 10-Q for the quarter ended March 31, 1998.

(A)        Indicates management contract or compensatory plan or arrangement.

(+)        Confidential treatment has been granted for certain portions of these
           exhibits.

(++)       Confidential treatment has been requested for certain portions of
           these exhibits.

(b)  REPORTS ON FORM 8-K

    Biosite did not file any report on Form 8-K in the quarter ended December
31, 1998.

                                      -44-

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED
                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the Company has duly caused this report to be signed on its behalf
of the undersigned, thereunto duly authorized.

BIOSITE DIAGNOSTICS INCORPORATED

 /s/ KIM D. BLICKENSTAFF                      Date:  March 31, 1999
- ---------------------------------------
         Kim D. Blickenstaff
 President and Chief Executive Officer

         Pursuant to the requirements of the Securities Exchange Act of 1934,
this report has been signed below by the following persons in the capacities and
on the date indicated.

<TABLE>
<CAPTION>
NAME                                  TITLE                                    DATE
- ----                                  -----                                    ----
<S>                                   <C>                                      <C>

     /s/ KIM D. BLICKENSTAFF          President, Chief Executive Officer       March 31, 1999
    ----------------------------      (Principal Executive Officer) and
        Kim D. Blickenstaff           Director


     /s/ CHRISTOPHER J. TWOMEY        Vice President and Chief Financial       March 31, 1999
    ----------------------------      Officer (Principal Financial Officer
       Christopher J. Twomey          and Accounting Officer)


     /s/ TIMOTHY J. WOLLAEGER         Chairman of the Board                    March 31, 1999
    ----------------------------
       Timothy J. Wollaeger


     /s/ ANTHONY DEMARIA              Director                                 March 31, 1999
    ----------------------------
       Anthony DeMaria, M.D.


     /s/ FREDERICK J. DOTZLER         Director                                 March 31, 1999
    ----------------------------
       Frederick J. Dotzler


     /s/ HOWARD E. GREENE, JR         Director                                 March 31, 1999
    ----------------------------
      Howard E. Greene, Jr


     /s/ LONNIE M. SMITH              Director                                 March 31, 1999
    ----------------------------
          Lonnie M. Smith


     /s/ GUNARS E. VALKIRS            Director                                 March 31, 1999
    ----------------------------
     Gunars E. Valkirs, Ph.D.
</TABLE>

                                      -45-

<PAGE>

                          INDEX TO FINANCIAL STATEMENTS

<TABLE>
<CAPTION>
                                                                           Page
                                                                           ----
<S>                                                                        <C>
Report of Ernst & Young LLP, Independent Auditors........................  F-2
Balance Sheets at December 31, 1997 and 1998.............................  F-3
Statements of Operations for each of the three years in the
  period ended December 31, 1998.........................................  F-4
Statements of Stockholders' Equity for each of the three
  years in the period ended December 31, 1998............................  F-5
Statements of Cash Flows for each of the three years in
  the period ended December 31, 1998.....................................  F-6
Notes to Financial Statements............................................  F-7
</TABLE>

                                      F-1

<PAGE>

                   REPORT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

The Board of Directors and Stockholders
Biosite Diagnostics Incorporated

    We have audited the accompanying balance sheets of Biosite Diagnostics
Incorporated as of December 31, 1997 and 1998, and the related statements of
operations, stockholders' equity and cash flows for each of the three years in
the period ended December 31, 1998. Our audits also included the financial
statement schedule listed in the Index at Item 14(a). These financial statements
and schedule are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements and
schedule based on our audits.

    We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

    In our opinion, the financial statements referred to above present fairly,
in all material respects, the financial position of Biosite Diagnostics
Incorporated at December 31, 1997 and 1998, and the results of its operations
and its cash flows for each of the three years in the period ended December 31,
1998 in conformity with generally accepted accounting principles. Also, in our
opinion, the related financial statement schedule, when considered in relation
to the basic financial statements taken as a whole, present fairly in all
material respects the information set forth therein.



                                                 ERNST & YOUNG LLP

San Diego, California
February 11, 1999,
except for Note 10, as to which the date is
March 29, 1999

                                      F-2

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                                 BALANCE SHEETS

<TABLE>
<CAPTION>
                                                                                        December 31,
                                                                                 1997                  1998
                                                                           ---------------       ---------------
<S>                                                                        <C>                   <C>
Assets
 Current assets:
  Cash and cash equivalents                                                 $   2,330,274         $     762,337
  Marketable securities, available-for-sale                                    36,927,167            33,466,841
  Accounts receivable                                                           5,282,500             6,573,735
  Receivable from stockholder                                                     648,664                    --
  Inventories                                                                   2,169,896             4,364,367
  Deferred income taxes                                                         2,310,000             1,666,000
  Prepaid expenses and other current assets                                     1,367,348             1,467,960
                                                                            -------------         -------------
        Total current assets                                                   51,035,849            48,301,240
Property, equipment and leasehold improvements,  net                            7,216,983             7,313,673
Deferred income taxes                                                             338,000             2,360,000
Patents and license rights, net                                                 3,720,035             7,203,433
Deposits and other assets                                                       1,000,341               630,765
                                                                            -------------         -------------
                                                                            $  63,311,208         $  65,809,111
                                                                            -------------         -------------
                                                                            -------------         -------------

Liabilities and stockholders' equity
Current liabilities:
  Accounts payable                                                          $   1,420,969         $   1,503,354
  Accrued salaries and other                                                    1,107,476             2,493,735
  Accrued costs for defense of patent matters                                           -             1,248,191
  Accrued contract payable                                                        563,812               205,928
  Current portion of long-term obligations                                      1,332,200             1,636,265
                                                                            -------------         -------------
        Total current liabilities                                               4,424,457             7,087,473
Long-term obligations                                                           3,796,975             4,038,444
Commitments and contingencies
Stockholders' equity:
   Preferred stock, $.01 par value, 5,000,000 shares authorized; no
    shares issued and outstanding at December 31, 1997 and 1998                         -                     -
   Common stock, $.01 par value, 25,000,000 shares authorized;
    12,864,745, and 12,926,706 shares issued and outstanding at
    December 31, 1997 and 1998, respectively                                      128,647               129,267
   Additional paid-in capital                                                  53,684,302            54,250,324
   Unrealized net gain on marketable securities, net of related tax
    effect of $3,772 and $23,510 at December 31, 1997 and 1998,
    respectively                                                                    5,658                35,266
   Deferred compensation                                                         (317,595)             (207,845)
   Retained earnings                                                            1,588,764               476,182
                                                                            -------------         -------------
        Total stockholders' equity                                             55,089,776            54,683,194
                                                                            -------------         -------------
                                                                            $  63,311,208         $  65,809,111
                                                                            -------------         -------------
                                                                            -------------         -------------
</TABLE>

See accompanying notes.

                                      F-3

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                            STATEMENTS OF OPERATIONS

<TABLE>
<CAPTION>
                                                                           Years Ended December 31,
                                                              1996                     1997                    1998
                                                       -----------------        ------------------      ------------------
<S>                                                    <C>                      <C>                     <C>
  Net sales                                            $      28,205,974        $       31,676,630      $       34,424,461
  Cost of sales                                                5,982,673                 6,925,318              10,513,524
                                                       -----------------        ------------------      ------------------
  Gross profit                                                22,223,301                24,751,312              23,910,937

  Operating expenses:
    Selling, general and administrative                        8,622,577                11,549,734              15,469,717
    Research and development                                   9,268,460                11,661,894              11,166,702
    Defense of patent matters                                  2,368,282                   330,537               4,860,857
                                                       -----------------        ------------------      ------------------
                                                              20,259,319                23,542,165              31,497,276
                                                       -----------------        ------------------      ------------------
  Operating income (loss)                                      1,963,982                 1,209,147              (7,586,339)

  Other income (expense):
    Interest income and other income                             744,342                 2,190,837               2,395,957
    Contract revenue-related parties                           1,101,649                   777,767                       -
    Contract revenue-unrelated parties                                 -                   466,500               2,629,800
    Reacquisition of distribution rights                               -                (3,364,134)                      -
                                                      ------------------       --------------------    -------------------
                                                               1,845,991                    70,970               5,025,757
  Income (loss) before benefit (provision) for
     income taxes                                              3,809,973                 1,280,117              (2,560,582)
  Benefit (provision) for income taxes                          (261,000)                  (82,000)              1,448,000
                                                       ------------------       -------------------     ------------------
  Net income (loss)                                    $       3,548,973        $        1,198,117      $       (1,112,582)
                                                       -----------------        ------------------      -------------------
                                                       -----------------        ------------------      -------------------

  Basic net income (loss) per share                    $            2.48        $             0.11      $            (0.09)
                                                       -----------------        ------------------      -------------------
                                                       -----------------        ------------------      -------------------
  Diluted  net income (loss) per share                 $             .34        $             .09       $            (0.09)
                                                       -----------------        ------------------      -------------------
                                                       -----------------        ------------------      -------------------

  Shares used in calculating per share amounts -
     Basic                                                     1,431,000                11,249,000              12,939,000
                                                       -----------------        ------------------      ------------------
                                                       -----------------        ------------------      ------------------
     Diluted                                                  10,392,000                13,081,000              12,939,000
                                                       -----------------        ------------------      ------------------
                                                       -----------------        ------------------      ------------------
</TABLE>

See accompanying notes.

                                      F-4

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED
                       STATEMENTS OF STOCKHOLDERS' EQUITY

<TABLE>
<CAPTION>
                                                                                                                       Additional   
                                                                   Preferred Stock               Common Stock            Paid-in    
                                                                Shares         Amount        Shares        Amount        Capital    
                                                              -----------    -------------  -----------  -----------  --------------
<S>                                                           <C>            <C>            <C>          <C>          <C>
Balance at December 31, 1995                                  8,328,847      $  83,288      1,369,595    $  13,696     $21,570,516  
Comprehensive income:
  Net income                                                                         -              -            -               -  
  Other comprehensive income, net of tax
    Change in unrealized net gain (loss) on marketable
      securities                                                                     -              -            -               -  
Comprehensive income                                                                 -              -            -               -  
Issuance of common stock under employee stock plans                                  -        103,978        1,040          85,185  
Deferred compensation related to issuance of stock options                           -              -            -         439,010  
Amortization of deferred compensation                                                -              -            -               -  
                                                             -----------     ---------     ----------    ---------    ------------  
Balance at December 31, 1996                                  8,328,847         83,288      1,473,573       14,736      22,094,711  
Comprehensive income:
  Net income                                                                         -              -            -               -  
  Other comprehensive income, net of tax
    Change in unrealized net gain (loss) on
      marketable securities                                                          -              -            -               -  
Comprehensive income                                                                 -              -            -               -  
Issuance of common stock from initial public
  offering (IPO), net of offering costs of $3,291,630                                -      2,760,000       27,600      29,800,770  
Conversion of preferred stock into common
  stock in connection with IPO                               (8,328,847)       (83,288)     8,328,847       83,288               -  
Conversion of convertible debenture into
  common stock in connection with IPO                                                -         92,575          926       1,109,978  
Issuance of common stock under employee stock plans                                  -        209,750        2,097         618,896  
Amortization of deferred compensation                                                -              -            -               -  
Income tax benefit from exercise of stock options                                    -              -            -          59,947  
                                                             -----------     ---------     ----------    ---------    ------------  
Balance at December 31, 1997                                                         -     12,864,745      128,647      53,684,302  

Comprehensive loss:
  Net loss                                                                           -              -            -               -  
  Other comprehensive income, net of tax
    Change in unrealized net gain (loss) on marketable
      securities                                                                     -              -            -               -  
Comprehensive loss                                                                   -              -            -               -  
Conversion of convertible debenture into common stock                                -         41,666          417         499,575  
Issuance of common stock under employee stock plans                                  -        142,695        1,427         812,620  
Repurchase and retirement of common stock                                            -       (122,400)      (1,224)       (841,173) 
Amortization of deferred compensation                                                -              -            -               -  
Income tax benefit from exercise of stock options                                    -              -            -          95,000  
                                                             -----------     ---------     ----------    ---------    ------------  
Balance at December 31, 1998                                                 $       -     12,926,706    $ 129,267    $ 54,250,324  
                                                             -----------     ---------     ----------    ---------    ------------  
                                                             -----------     ---------     ----------    ---------    ------------  

<CAPTION>
                                                                Accumulated                          Retained                     
                                                                   Other                             Earnings/         Total      
                                                               Comprehensive        Deferred        (Accumulated     Stockholders'
                                                                   Income         Compensation        Deficit)          Equity    
                                                               -------------     --------------   ----------------  --------------
<S>                                                            <C>               <C>              <C>               <C>           
Balance at December 31, 1995                                      $16,588          $        -     $  (3,158,326)    $  18,525,762 
Comprehensive income:                                                                                                             
  Net income                                                            -                   -         3,548,973         3,548,973 
  Other comprehensive income, net of tax                                                                                          
    Change in unrealized net gain (loss) on marketable                                                                            
      securities                                                  (19,342)                  -                 -           (19,342)
                                                                                                                    --------------
Comprehensive income                                                    -                   -                 -         3,529,631 
                                                                                                                    --------------
Issuance of common stock under employee stock plans                     -                   -                 -            86,225 
Deferred compensation related to issuance of stock options              -            (439,010)                -                 - 
Amortization of deferred compensation                                   -              11,665                 -            11,665 
                                                                ---------          ----------        ----------     ------------- 
Balance at December 31, 1996                                       (2,754)           (427,345)          390,647        22,153,283 
Comprehensive income:                                                                                                             
  Net income                                                            -                   -         1,198,117         1,198,117 
  Other comprehensive income, net of tax                                                                                          
    Change in unrealized net gain (loss) on                                                                                       
      marketable securities                                         8,412                   -                 -             8,412 
                                                                                                                    --------------
Comprehensive income                                                    -                   -                 -         1,206,529 
                                                                                                                    --------------
Issuance of common stock from initial public                                                                                      
  offering (IPO), net of offering costs of $3,291,630                   -                   -                 -        29,828,370 
Conversion of preferred stock into common                                                                                         
  stock in connection with IPO                                          -                   -                 -                 - 
Conversion of convertible debenture into                                                                                          
  common stock in connection with IPO                                   -                   -                 -         1,110,904 
Issuance of common stock under employee stock plans                     -                   -                 -           620,993 
Amortization of deferred compensation                                   -             109,750                 -           109,750 
Income tax benefit from exercise of stock options                       -                   -                 -            59,947 
                                                                ---------          ----------        ----------     ------------- 
Balance at December 31, 1997                                        5,658            (317,595)        1,588,764        55,089,776 
                                                                                                                                  
Comprehensive loss:                                                                                                               
  Net loss                                                              -                   -        (1,112,582)       (1,112,582)
  Other comprehensive income, net of tax                                                                                          
    Change in unrealized net gain (loss) on marketable                                                                            
      securities                                                   29,608                   -                 -            29,608 
                                                                                                                    --------------
Comprehensive loss                                                      -                   -                 -        (1,082,974)
                                                                                                                    --------------
Conversion of convertible debenture into common stock                   -                   -                 -           499,992 
Issuance of common stock under employee stock plans                     -                   -                 -           814,047 
Repurchase and retirement of common stock                               -                   -                 -          (842,397)
Amortization of deferred compensation                                   -             109,750                 -           109,750 
Income tax benefit from exercise of stock options                       -                   -                 -            95,000 
                                                                ---------          ----------        ----------     ------------- 
Balance at December 31, 1998                                    $  35,266          $ (207,845)       $  476,182     $  54,683,194 
                                                                ---------          -----------       ----------     ------------- 
                                                                ---------          -----------       ----------     ------------- 
</TABLE>

See accompanying notes

                                     F-5

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                            STATEMENTS OF CASH FLOWS

<TABLE>
<CAPTION>

                                                                                   Year ended December 31,
                                                                          1996               1997               1998
                                                                     -------------      --------------    --------------
<S>                                                                  <C>                <C>               <C>
OPERATING ACTIVITIES:
Net income (loss)                                                    $   3,548,973      $    1,198,117    $   (1,112,582)
Adjustments to reconcile net income (loss) to net cash provided
  by operating activities:
  Depreciation and amortization                                          2,417,816           2,738,230         4,608,081
  Amortization of deferred compensation                                     11,665             109,750           109,750
  Deferred income taxes                                                    110,000            (931,000)       (1,378,000)
  Changes in operating assets and liabilities:
    Accounts receivable                                                   (806,317)           (674,428)       (1,291,235)
    Receivable from stockholder                                           (728,535)            220,871           648,664
    Inventory                                                              (43,056)           (437,716)       (2,194,471)
    Prepaid expenses and other current assets                             (257,486)           (688,659)         (120,350)
    Accounts payable                                                       191,581             452,995            82,385
    Accrued liabilities                                                 (1,462,967)           (860,205)        1,321,558
    Deferred revenue from stockholder                                     (615,282)                  -                 -
                                                                     -------------      --------------    --------------
Net cash provided by operating activities                                2,366,392           1,127,955           673,800

INVESTING ACTIVITIES:
Proceeds from sales and maturities of marketable securities             13,019,169          37,340,473        33,898,842
Purchase of marketable securities                                       (9,654,462)        (65,947,956)      (30,389,170)
Purchase of property, equipment and leasehold improvements              (1,967,143)         (5,221,969)       (3,091,536)
Patents, license rights, deposits and other assets                      (4,929,555)          1,108,389        (3,677,057)
                                                                     -------------      --------------    --------------
Net cash used in investing activities                                   (3,531,991)        (32,721,063)       (3,258,921)

FINANCING ACTIVITIES:
Proceeds from issuance of convertible debenture                                  -                   -           500,000
Proceeds from issuance of equipment loans payable                        1,641,340           3,077,701         1,993,123
Principal payments under long-term obligations                          (1,228,508)         (1,213,543)       (1,447,589)
Proceeds from issuance of stock, net                                        86,225          30,449,363           814,047
Repurchase of common stock, net                                                  -                   -          (842,397)
                                                                     -------------      --------------    --------------
Net cash provided by financing activities                                  499,057          32,313,521         1,017,184
                                                                     -------------      --------------    --------------

Increase (decrease) in cash and cash equivalents                          (666,542)            720,413        (1,567,937)
Cash and cash equivalents at beginning of year                           2,276,403           1,609,861         2,330,274
                                                                     -------------      --------------    --------------
Cash and cash equivalents at end of year                             $   1,609,861      $    2,330,274    $      762,337
                                                                     -------------      --------------    --------------
                                                                     -------------      --------------    --------------

Supplemental disclosures of cash flow information:
  Interest paid                                                      $     280,245      $      356,694    $      320,008
                                                                     -------------      --------------    --------------
                                                                     -------------      --------------    --------------
  Income taxes paid                                                  $     103,350      $    1,203,900    $        5,400
                                                                     -------------      --------------    --------------
                                                                     -------------      --------------    --------------

Supplemental schedule of non-cash investing and financing
  activities:
  Conversion of convertible debenture into common stock              $           -      $    1,110,904    $      499,992
                                                                     -------------      --------------    --------------
                                                                     -------------      --------------    --------------
  Accrued liability for license rights acquired                      $           -      $            -    $    1,050,000
                                                                     -------------      --------------    --------------
                                                                     -------------      --------------    --------------
</TABLE>

See accompanying notes.

                                      F-6

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

1. Organization and Summary of Significant Policies

ORGANIZATION AND BUSINESS ACTIVITY

    Biosite Diagnostics Incorporated (the "Company") was established in 1988. 
The Company has been primarily involved in the research, development, 
manufacturing and marketing of rapid diagnostic tests. In 1992, the Company 
began commercial sales of the Company's primary product, Triage Panel for 
Drugs of Abuse ("Triage DOA Panel"), and currently markets the product 
worldwide primarily through distributors supported by the Company's direct 
sales force. In 1998, the Company began selling three additional products, 
the Triage C. DIFFICILE Panel, the Triage Parasite Panel and the Triage 
Cardiac System. In addition to focusing its attention on commercial 
activities associated with these products, the Company continues to invest in 
the research and development of additional rapid tests to aid in the 
diagnosis of several critical diseases or conditions, including congestive 
heart failure and certain bacterial infections. The Company also is 
developing a diagnostic test to aid in the dosing of immunosuppressant drugs. 
The principal markets of the Company are hospital laboratories and emergency 
departments.

    During the first quarter of 1998, the Company received final clearance 
from the U.S. Food and Drug Administration ("FDA") to market the Triage 
Cardiac Panel and the Triage Meter (together called "Triage Cardiac System") 
and the Triage C. DIFFICILE Panel in the United States. The Triage Cardiac 
System is Biosite's first product to utilize the Company's Triage Meter 
System technology and is designed to deliver precise, quantitative results in 
a rapid timeframe. The Triage Cardiac System may aid in the diagnosis of 
Acute Myocardial Infarction ("AMI") and provide physicians with an enhanced 
ability to make treatment decisions in a timely manner. Used in conjunction 
with the Triage Meter, the Triage Cardiac Panel quantitatively measures, in a 
single test device, the level of CK-MB, troponin I and myoglobin from a 
whole-blood sample. The Triage C. DIFFICILE Panel is a rapid test designed to 
identify CLOSTRIDIUM DIFFICILE, an opportunistic pathogen of the intestinal 
tract that may thrive as a result of broad spectrum antibiotic treatment. The 
Company began selling the Triage C. DIFFICILE Panel in March and the Triage 
Cardiac System in May. In October 1998, the Company received final clearance 
from the FDA to market the Triage Parasite Panel, the Company's third product 
launched in 1998. The Triage Parasite Panel is a rapid test designed to 
simultaneously detect three common waterborne parasites, GIARDIA LAMBLIA, 
CRYPTOSPORIDIUM PARVUM and ENTAMOEBA HISTOLYTICA/DISPAR, that can cause 
severe gastrointestinal infections. Sales of the Triage Parasite Panel were 
initiated in mid-October.

REVENUE RECOGNITION AND SIGNIFICANT CUSTOMERS

    The Company recognizes sales upon shipment.  The Company's U.S. 
distributor accounted for 81%, 80% and 86% of the product sales in 1996, 1997 
and 1998, respectively.

    Export sales to international customers amounted to $2,846,000, 
$2,982,000 and $2,749,000 in 1996, 1997 and 1998, respectively. Sales to a 
stockholder amounted to approximately $2,096,000 and $2,013,000 in 1996 and 
1997, respectively. The stockholder disposed of its Biosite common stock 
holding in 1998. Trade accounts receivable from the stockholder was 
approximately $649,000 at December 31, 1997.

    The Company records revenues under collaborative development agreements, 
based on the performance criteria of each contract, either as milestones are 
earned or on the percentage of completion basis as cost are incurred.

CASH AND CASH EQUIVALENTS

    Cash and cash equivalents consist of cash and highly liquid investments 
in debt securities with maturities of 90 days or less when purchased.

                                      F-7

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

MARKETABLE SECURITIES

    Financial Accounting Standards Board ("FASB") Statement No. 115, Accounting
for Certain Investments in Debt and Equity Securities, requires that investments
in equity securities that have readily determinable fair values and investments
in debt securities be classified in three categories: held-to-maturity, trading
and available-for-sale. Based on the nature of the assets held by the Company
and management's investment strategy, the Company's investments have been
classified as available-for-sale. Management determines the appropriate
classification of debt securities at the time of purchase and reevaluates such
designation as of each balance sheet date. Securities classified as
available-for-sale are carried at estimated fair value, as determined by quoted
market prices, with unrealized gains and losses, net of tax, reported in a
separate component of stockholders' equity. At December 31, 1998, the Company
had no investments that were classified as trading or held-to-maturity as
defined by the Statement. The amortized cost of debt securities classified as
available-for-sale is adjusted for amortization of premiums and accretion of
discounts to maturity. Such amortization is included in interest income.
Realized gains and losses are included in interest income. The cost of
securities sold is based on the specific identification method. Interest on
securities classified as available-for-sale is included in interest income.

INVENTORIES

    Inventories are carried at the lower of cost (first-in, first-out) or
market.

PROPERTY, EQUIPMENT AND LEASEHOLD IMPROVEMENTS

    Property, equipment and leasehold improvements are stated at cost.

DEPRECIATION AND AMORTIZATION

    Depreciation of property and equipment is computed using the straight-line
method over five years. Amortization of leasehold improvements is computed using
the straight-line method over the shorter of the estimated useful lives of the
assets or the remaining lease term.

PATENTS AND LICENSE RIGHTS

    The Company has been issued patents covering its threshold immunoassay and
other related technologies. Capitalized patent costs associated with issued
patents are amortized over five to seventeen years. License rights related to
products for sale are amortized to cost of sales over the life of the license,
not to exceed ten years, using a systematic method based on the estimated
revenues generated from products during such license period.

STOCK OPTIONS

    The Company has elected to follow Accounting Principles Board Opinion No.
25, Accounting for Stock Issued to Employees (APB 25) and related
interpretations in accounting for its stock options. For options granted during
the one-year period prior to the Company's initial public offering of common
stock, the Company recorded and amortizes, over the related vesting periods,
deferred compensation representing the excess of the value for accounting
purposes of the options granted over their aggregate exercise price.

                                      F-8

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

CONCENTRATION OF CREDIT RISK

    The Company sells its products primarily to its U.S. distributor. Credit is
extended based on an evaluation of the customer's financial condition, and
generally collateral is not required. Credit losses have been minimal and within
management's expectations.

    The Company invests its excess cash in debt instruments of the U.S.
Government, financial institutions and corporations with strong credit ratings.
The Company has established guidelines relative to diversification and
maturities that maintain safety and liquidity. These guidelines are periodically
reviewed and modified to take advantage of trends in yields and interest rates.
The Company has not experienced any significant realized losses on its
marketable securities.

USE OF ESTIMATES

    The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the reported amounts of assets and liabilities and the
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. Actual results could differ from those estimates.

EARNINGS PER SHARE

    In February 1997, the Financial Accounting Standards Board issued 
Statement of Financial Accounting Standards No. 128, Earnings per Share 
("Statement No. 128"). Statement No. 128 applies to entities with publicly 
held common stock or potential common stock and is effective for financial 
statements issued for periods ending after December 15, 1997. Statement No. 
128 replaces APB Opinion 15, Earnings per Share ("EPS"). Statement No. 128 
requires dual presentation of basic and diluted earnings per share by 
entities with complex capital structures. Basic EPS includes no dilution and 
is computed by dividing net income by the weighted average number of common 
shares outstanding for the period. Diluted EPS reflects the potential 
dilution of securities that could share in the earnings of the Company such 
as common stock which may be issuable upon exercise of outstanding common 
stock options.

    Shares used in calculating basic and diluted net income per share were as
follows:

<TABLE>
<CAPTION>
                                                                           YEAR ENDED DECEMBER 31,
                                                                ----------------------------------------------
                                                                     1996            1997           1998
                                                                ---------------- -------------- --------------
<S>                                                             <C>              <C>            <C>
Shares used in calculating per share amounts - Basic
   (Weighted average common shares outstanding)                          1,431         11,249         12,939

Effect of common share equivalents:
  Assumed conversion of preferred shares                                 8,329          1,110              -
  Assumed conversion of convertible debenture                               92             12              -
  Net effect of dilutive common stock options using the
   treasury stock method                                                   540            699              -
  Contingently issuable shares                                               -             11              -
                                                                ---------------- -------------- --------------
Shares used in calculating per share amounts - Diluted                  10,392         13,081         12,939
                                                                ---------------- -------------- --------------
                                                                ---------------- -------------- --------------
</TABLE>

                                      F-9

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

COMPREHENSIVE INCOME

    In June 1997, the Financial Accounting Standards Board issued SFAS No. 
130, Reporting Comprehensive Income, which became effective for fiscal years 
beginning after December 15, 1997. SFAS No. 130 requires that all components 
of comprehensive income, including net income, be reported in the financial 
statements in the period in which they are recognized. Comprehensive income 
is defined as the change in equity during a period from transactions and 
other events and circumstances from non-owner sources. Net income and other 
comprehensive income, including foreign currency translation adjustments, and 
unrealized gains and losses on investments, shall be reported, net of their 
related tax effect, to arrive at comprehensive income. Included in the 
Company's statements of equity, other comprehensive income consisting of 
unrealized gains and losses on investments are reported. Comprehensive income 
or loss was not materially different than net income or loss.

SEGMENT INFORMATION

    In June 1997, the Financial Accounting Standards Board issued SFAS No. 
131, Segment Information, which became effective for fiscal years beginning 
after December 15, 1997. SFAS No. 131 amends the requirements for public 
enterprises to report financial and descriptive information about its 
reportable operating segments. Operating segments, as defined in SFAS No. 
131, are components of an enterprise for which separate financial information 
is available and is evaluated regularly by the Company in deciding how to 
allocate resources and in assessing performance. The financial information is 
required to be reported on the basis that is used internally for evaluating 
the segment performance. The Company believes it operates in one business and 
operating segment and that adoption of this standard did not have a material 
impact on the Company's financial statements.

2. Licensing Agreements

    The Company has entered into licensing agreements to utilize certain 
antibodies and/or technologies in exchange for up-front, annual milestone, or 
royalty payments or a combination thereof. Certain of the upfront and annual 
payments are creditable towards future royalties payable. Royalties may be 
payable at various rates for product sales derived from the licensed 
technologies.

The Company purchased license rights for technologies utilized in products 
for sale of $3.5 million, $0, and $5.0 million during the years ended 
December 31, 1996, 1997 and 1998, respectively. Accumulated amortization of 
license rights at December 31, 1996, 1997 and 1998 was approximately $1.8 
million, $2.4 million and $4.0 million, respectively

3. Collaborative and Distribution Agreements

    In 1997, the Company successfully completed feasibility studies for the 
NeoralChek System under its antibody license agreement with Novartis Pharma 
AG ("Novartis"). As a result of this milestone achievement, Novartis 
invested, in January 1998, an additional $500,000 in Biosite in exchange for 
a convertible debenture. The convertible debenture was immediately converted 
into 41,666 shares of common stock of the Company based on the IPO price of 
$12.00 per share. Additionally, the Company and Novartis entered into an 
agreement to expand the scope of the collaborative development of the 
NeoralChek System. For the years ended December 31, 1997 and 1998, the 
Company recognized contract revenues of $400,000 and $1.1 million, 
respectively. The expansion of the collaboration may result in additional 
payments to Biosite upon attainment of milestones.

    In February 1995, the Company entered into a collaborative development 
and distribution agreement that included the Asian marketing rights to the 
Triage Cardiac Panel under development. Under this agreement, the Company 
will receive up to $2.0 million upon the completion of certain milestones. 
Recognition of revenue under this agreement will occur as the milestones are 
attained. For the year ended December 31, 1998, the Company recognized 
contract revenues of $1.3 million for the completion of certain milestones 
under the agreement.

                                      F-10

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

    In June 1994, the Company entered into a collaborative development 
agreement and a distribution agreement with Merck KgaA ("Merck"), a former 
stockholder, for the development and marketing of the Triage Cardiac Panel 
and under such agreements, Merck was to fund a portion of the development 
costs. The Company recognized revenue under this agreement on the percentage 
of completion basis as costs were incurred. For the years ended December 31, 
1996 and 1997, the Company incurred $2,554,000 and $2,866,000, respectively, 
in expenses under this agreement and recognized $1,102,000 and $778,000 
respectively, as contract revenue.

    As a result of a decision by Merck to refocus away from certain aspects 
of the human diagnostic business, in 1997, the Company terminated agreements 
with Merck for the development and distribution of the Triage Cardiac System 
and the distribution of the Triage DOA Panel product line. Upon termination, 
the Company paid a $2.1 million cash payment and forgave approximately $1.3 
million owed to the Company by Merck related to the development of the Triage 
Cardiac System. Such expenses were charged to reacquisition of distribution 
rights in the accompanying statements of operations. During the last half of 
1998, the Company finalized alliances with several European partners, forming 
a network of distributors to market its products in certain European 
countries.

4. Cash, Cash Equivalents and Marketable Securities

    The following is a summary of cash, cash equivalents and available-for-sale
marketable securities by balance sheet classification at December 31, 1997:

<TABLE>
<CAPTION>
                                                                                  Gross          Gross            Estimated
                                                               Amortized       Unrealized      Unrealized            Fair
                                                                  Cost            Gains          Losses              Value
                                                              -------------    ------------    -----------      ------------
<S>                                                           <C>              <C>             <C>              <C>         
Cash and cash equivalents:
  Cash                                                        $  1,052,970       $       -     $        -       $   1,052,970
  Money market fund                                                285,394               -              -             285,394
  Commercial paper                                                 991,910               -              -             991,910
                                                              ------------       ---------     ----------       -------------
                                                                 2,330,274               -              -           2,330,274
Marketable securities:
  Certificates of deposit                                        2,093,829               -             (4)          2,093,825
  U.S. Government debt securities                                4,010,950          11,070              -           4,022,020
  Corporate debt securities                                     30,812,958             935         (2,571)         30,811,322
                                                              ------------       ---------     ----------       -------------
                                                                36,917,737          12,005         (2,575)         36,927,167
                                                              ------------       ---------     ----------       -------------
Total cash, cash equivalents and available-for-sale
  marketable securities                                       $ 39,248,011       $  12,005     $   (2,575)      $  39,257,441
                                                              ------------       ---------     ----------       -------------
                                                              ------------       ---------     ----------       -------------
</TABLE>


    The following is a summary of cash, cash equivalents and available-for-sale
securities by balance sheet classification at December 31, 1998:

<TABLE>
<CAPTION>
                                                                                  Gross          Gross            Estimated
                                                               Amortized       Unrealized      Unrealized            Fair
                                                                  Cost            Gains          Losses              Value
                                                              -------------    ------------    -----------      ------------
<S>                                                           <C>              <C>             <C>              <C>         
Cash and cash equivalents:                                                                                      
  Cash                                                        $    449,352       $       -     $        -       $     449,352
  Corporate debt securities                                        312,985               -              -             312,985
                                                              ------------       ---------     ----------       -------------
                                                                   762,337               -              -             762,337
Marketable securities:
  Certificate of deposit                                         2,005,724           1,784              -           2,007,508
  U.S. Government debt securities                                  499,182           1,133              -             500,315
  Corporate debt securities                                     30,903,159          79,836        (23,977)         30,959,018
                                                              ------------       ---------     ----------       -------------
                                                                33,408,065          82,753        (23,977)         33,466,841
                                                              ------------       ---------     ----------       -------------
Total cash, cash equivalents and available-for-sale
  marketable securities                                       $ 34,170,402       $  82,753     $  (23,977)      $  34,229,178
                                                              ------------       ---------     ----------       -------------
                                                              ------------       ---------     ----------       -------------
</TABLE>

                                      F-11

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

    The amortized cost and estimated fair value of available-for-sale securities
at December 31, 1998, by contractual maturity, are as follows:

<TABLE>
<CAPTION>
                                                                    Amortized          Estimated
                                                                       Cost            Fair Value
                                                                  -------------       -------------
         <S>                                                      <C>                 <C>
         Marketable securities:
           Due in one year or less                                $  21,166,327       $ 21,197,915
           Due after one year through two years                      12,241,738         12,268,926
                                                                  -------------       ------------
                                                                  $  33,408,065       $ 33,466,841
                                                                  -------------       ------------
                                                                  -------------       ------------
</TABLE>

5. Balance Sheet Information

Inventories consist of the following:

<TABLE>
<CAPTION>
                                                                              December 31,
                                                                     1997                       1998
                                                                -------------               -------------
<S>                                                             <C>                         <C>
Raw materials                                                   $    779,965                $  1,405,176
Work in process                                                    1,214,894                   2,938,548
Finished goods                                                       175,037                      20,643
                                                                ------------                ------------
                                                                $  2,169,896                $  4,364,367
                                                                ------------                ------------
                                                                ------------                ------------
</TABLE>

Property, equipment and leasehold improvements consist of the following:

<TABLE>
<CAPTION>
                                                                              December 31,
                                                                      1997                      1998
                                                                -------------              -------------
<S>                                                             <C>                        <C>
Machinery and equipment                                         $  10,655,422              $  12,936,671
Furniture and fixtures                                                836,933                    986,368
Leasehold improvements                                              2,564,894                  3,225,746
                                                                -------------              -------------
                                                                   14,057,249                 17,148,785
Less accumulated depreciation and amortization                     (6,840,266)                (9,835,112)
                                                                -------------              -------------
                                                                $   7,216,983              $   7,313,673
                                                                -------------              -------------
                                                                -------------              -------------
</TABLE>

6. Debt and Commitments

Debt consisted of the following:

<TABLE>
<CAPTION>
                                                                          December 31,
                                                                 1997                       1998
                                                         -------------------        -------------------
<S>                                                       <C>                        <C> 
Equipment financing notes, payable $179,901
  monthly including interest at 6.59% to 9.65%;
  due January 1999 to December 2003; secured by
  equipment                                                 $   5,129,175              $   5,674,709

Less current portion                                            1,332,200                  1,636,265
                                                            -------------              -------------
Total long-term obligations                                 $   3,796,975              $   4,038,444
                                                            -------------              -------------
                                                            -------------              -------------
</TABLE>

    As a result of the attainment of one of the milestones (the successful
completion of feasibility studies for the Triage Neoral System under
development), the Company received $500,000 from Novartis, in January 1998, in
exchange for a convertible debenture. The convertible debenture was immediately
converted into 41,666 shares of common stock of the Company based on the IPO
price of $12.00 per share. The Company is obligated to sell to Novartis an
additional $500,000 five-year 8% convertible debenture upon the attainment of a
certain milestone. The debenture would be convertible, at the sole option of the
Company, into shares of Biosite common stock at $12.00 per share.

                                      F-12

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

    As of December 31, 1998, approximate future principal payments of the
equipment financing notes are due as follows: 1999 - $1,636,000; 2000 -
$1,575,000; 2001 - $1,304,000; 2002 - $876,000; and 2003 - $284,000.

    Interest charged to expense to arrive at operating income (loss) was
approximately $360,000, $357,000, and $320,000 for the years ended December 31,
1996, 1997, and 1998, respectively.

    The Company leases its office, manufacturing and research facilities under
operating leases. The minimum annual rent on the facilities is subject to
increases based on changes in the Consumer Price Index, taxes, insurance and
operating costs, subject to certain minimum and maximum annual increases. The
Company has options to renew certain of the facilities leases for a period of
two years. Included in deposits and other assets in the accompanying balance
sheets is approximately $199,000 and $85,000 of security deposits in conjunction
with operating lease and equipment financing agreements at December 31, 1997 and
1998, respectively.

Approximate annual future minimum operating lease payments as of December 31,
1998 are as follows:

<TABLE>
<CAPTION>
                                                                  Operating
      Year                                                          Leases
      ----                                                      --------------
      <S>                                                       <C>
      1999                                                        $1,071,000
      2000                                                         1,155,000
      2001                                                           230,000
      2002                                                           234,000
      2003                                                            60,000
                                                                   ---------
           Total minimum lease payments                           $2,750,000
                                                                  ----------
                                                                  ----------
</TABLE>

    Rent expense for the years ended December 31, 1996, 1997 and 1998 was
approximately $876,000, $1,033,000 and $879,000 respectively. Equipment under
equipment financing notes was approximately $6,478,000 and $8,510,000 at
December 31, 1997, and 1998, respectively. Accumulated depreciation of equipment
under equipment financing at December 31, 1997 and 1998 was approximately
$1,874,000 and $3,607,000, respectively.

7. Stockholders' Equity

INITIAL PUBLIC OFFERING

    In February 1997, the Company completed its initial public offering of
2,760,000 shares of common stock (including an exercised underwriters'
over-allotment option for 360,000 shares) at a price of $12.00 per share,
providing the Company with net proceeds of approximately $29.8 million.
Additionally, all outstanding shares of preferred stock were converted into
8,328,847 shares of common stock and an outstanding $1.0 million convertible
debenture and related accrued interest was converted into 92,575 common shares
upon the completion of the IPO.

STOCK PLANS

    The Company's 1989 Stock Plan provided for both the direct sale of common
stock and for the grant of options to purchase common stock to employees,
directors, consultants and advisors of the Company. As of December 31, 1998,
144,476 shares have been sold directly under the plan and no shares were
available for future issuance of common stock or grant of options to purchase
common stock under the 1989 Stock Plan.

                                      F-13

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)


    In December 1996, the Company adopted the 1996 Stock Incentive Plan (the
"1996 Stock Plan"). The 1996 Stock Plan replaced the Company's 1989 Stock Plan.
Although all future awards will be made under the 1996 Stock Plan, awards made
under the 1989 Stock Plan will continue to be administered in accordance with
the 1989 Stock Plan. The 1996 Stock Plan provides for awards in the form of
restricted shares, stock units, options or stock appreciation rights or any
combination thereof. As of December 31, 1998, a pool of 1,400,000 shares has
been reserved for issuance under the 1996 Stock Plan. Additionally, any
unpurchased shares of common stock pursuant to unissued, expired or cancelled
options under the 1989 Stock Plan become available for awards under the 1996
Stock Plan.

    The options are generally subject to four year vesting and expire ten years
from the date of grant. At December 31, 1998, 108,519 shares were available for
future issuance of common stock or grant of options to purchase common stock
under the 1996 Stock Plan.

Information with respect to the Company's 1989 Stock Plan and 1996 Stock Plan
option activity is as follows:

<TABLE>
<CAPTION>
                                                                                                 Weighted
                                                                                                 average
                                                                                                 exercise
                                                                                  Shares          price
                                                                                 --------       ----------
    <S>                                                                          <C>            <C>
    Balance at December 31, 1995                                                  788,255        $  1.63
      Granted at fair value                                                       957,500        $  6.45
      Exercised                                                                  (103,978)       $  0.83
      Cancelled                                                                  (359,797)       $  7.87
                                                                                 --------        -------
    Balance at December 31, 1996                                                1,281,980        $  3.46
      Granted at fair value                                                       388,400        $  9.93
      Exercised                                                                  (154,996)       $  1.27
      Cancelled                                                                   (75,661)       $  5.65
                                                                                  -------        -------
    Balance at December 31, 1997                                                1,439,723        $  5.33
    Granted at fair value                                                         968,025        $ 12.30
      Exercised                                                                   (71,391)       $  3.06
      Cancelled                                                                   (64,777)       $  9.66
                                                                                  -------        -------
    Balance at December 31, 1998                                                2,271,580        $  8.25
                                                                                ---------        -------
                                                                                ---------        -------
</TABLE>

The following is a further breakdown of the options outstanding under the 1989
Stock Plan and 1996 Stock Plan as of December 31, 1998:

<TABLE>
<CAPTION>
                                             Weighted
                                              average                                                    Weighted
                                             remaining           Weighted                            average exercise
 Range of exercise         Options        contractual life   average exercise        Options         price of options
       price             outstanding          in years            price            exercisable         exercisable
- ----------------------------------------------------------------------------------------------------------------------
<S>                      <C>              <C>                <C>                   <C>               <C>
$0.24  - $3.75             535,610              5.71             $ 2.16               470,232             $ 1.99
$5.06  - $7.25             558,676              7.98             $ 5.61               282,341             $ 5.59
$7.88  - $13.25            532,976              8.80             $10.01               159,790             $10.26
$13.88 - $16.31            644,318              9.37             $14.14               103,893             $14.19
- ----------------------------------------------------------------------------------------------------------------------
$0.24  - $16.31          2,271,580              8.03             $ 8.25             1,016,256             $ 5.54
- ----------------------------------------------------------------------------------------------------------------------
- ----------------------------------------------------------------------------------------------------------------------
</TABLE>

                                      F-14

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

    Adjusted pro forma information regarding net income is required by SFAS 123,
and has been determined as if the Company had accounted for its employee stock
options under the fair value method of that Statement. The fair value for these
options was estimated at the date of grant using the Black-Scholes method for
option pricing with the following weighted-average assumptions for 1996, 1997,
and 1998:

<TABLE>
<CAPTION>
                              1996                         1997                         1998
                              --------------------------------------------------------------
                              <S>                          <C>                          <C>
Risk-free interest rate       6%                           6%                           5.25%
Volatility                    55%                          55%                          83%
Dividend yield                0%                           0%                           0%
Expected life of options      6 years                      6 years                      5 years
</TABLE>


    For purposes of adjusted pro forma disclosures, the estimated fair value of
the options is amortized to expense over the options' vesting period. The
Company's adjusted pro forma information follows:

<TABLE>
<CAPTION>
                                                                    Years ended December 31,
                                                           1996               1997           1998
                                                           ----               ----           ----
<S>                                                    <C>               <C>            <C>
Adjusted pro forma net income (loss)                   $ 3,201,956       $   430,973    $ (3,256,548)
Adjusted pro forma diluted net income (loss)
  per share                                            $      0.31       $      0.03    $      (0.25)
</TABLE>

    The pro forma effects on net income for 1996, 1997, and 1998 are not likely
to be representative of the effects on reported net income or loss in future
years. In management's opinion, existing stock option valuation models do not
provide a reliable single measure of the fair value of employee stock options
that have vesting provisions and are not transferable. In addition, option
valuation models require the input of highly subjective assumptions, including
expected stock price volatility. Changes in such subjective input assumptions
can materially affect the fair value estimate of employee stock options.

EMPLOYEE STOCK PURCHASE PLAN

    In December 1996, the Company adopted an Employee Stock Purchase Plan
("ESPP") which provides employees the opportunity to purchase common stock at a
discount and pay for such purchases through payroll deductions, subject to
certain limitations. A pool of 350,000 shares of common stock has been reserved
for issuance under the ESPP (subject to anti-dilution provisions). During the
years ended December 31, 1997 and 1998, 54,754 and 71,304 shares, respectively,
were issued under the ESPP. As of December 31, 1998, 223,942 shares of common
stock were available for issuance under the ESPP.

At December 31, 1998, a total of 2,604,041 shares of the Company's common stock
were reserved for future issuances under the Company's stock plans and employee
stock purchase plan.

STOCK REPURCHASE PROGRAM

    In September 1998, the Company initiated a common stock repurchase program,
under which it may purchase up to one million shares of its common stock. The
duration of the repurchase program is open-ended. Under the program, Biosite may
purchase shares of its common stock from time to time through open market and
privately negotiated transactions at prices deemed appropriate by its
management. During 1998, the Company repurchased 122,400 shares of its common
stock at a total cost of approximately $842,000.

                                      F-15

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

SHAREHOLDERS' RIGHTS PLAN

    In October, 1997, the Board of Directors of the Company declared a dividend
distribution of one preferred stock purchase right (a "Right") for each
outstanding share of common stock of Biosite held of record at the close of
business on November 3, 1997. Each Right represents a contingent right to
purchase, under certain circumstances, one-one-thousandth of a share of a new
series of Biosite preferred stock at a price of $50.00 per one one-thousandth of
a share, subject to adjustment. The Rights would be traded independently from
Biosite's common stock and become exercisable under certain circumstances
involving the acquisition or a tender or exchange offer by a person or group for
15% or more of Biosite's common stock. The Rights expire on October 22, 2007,
unless redeemed by the Company's Board of Directors. The Rights can be redeemed
by the Board at a price of $0.01 per Right at any time before the Rights become
exercisable, and in limited circumstances thereafter.

8. Income Taxes

    Significant components of the income tax benefit (provision) are as follows:

<TABLE>
<CAPTION>
                                               Years Ended December 31,
                                       1996             1997               1998
                                   ------------     -------------      -----------
    <S>                            <C>              <C>                <C>
    Current:
      Federal                      $  (146,000)     $   (555,000)      $    69,000
      State                             (5,000)         (458,000)            1,000
                                   ------------     -------------      -----------
                                      (151,000)       (1,013,000)           70,000
    Deferred:
      Federal                         (304,000)          499,000         1,053,000
      State                            194,000           432,000           325,000
                                   ------------     -------------      -----------
                                      (110,000)          931,000         1,378,000
                                   ------------     -------------      -----------
                                   $  (261,000)     $    (82,000)      $ 1,448,000
                                   ------------     -------------      -----------
                                   ------------     -------------      -----------
</TABLE>

    As of December 31, 1998, the Company had federal research and development,
California research and development, and California manufacturers' credit
carryforwards of approximately $1,552,000, $685,000, and $425,000, respectively.
The federal research and development, California research and development, and
California manufacturers' credits will begin expiring in 2003, 2003, and 2005,
respectively, unless previously utilized.

    Significant components of the Company's deferred tax assets as of December
31, 1997 and 1998 are shown below.

<TABLE>
<CAPTION>
                                                                                   December 31,
                                                                             1997               1998
                                                                         -----------        -----------
      <S>                                                                <C>                <C>
      Deferred tax assets:
        Research and development credit                                  $ 1,511,000        $ 1,997,000
        Federal and California Alternative Minimum Tax credit                203,000            277,000
        California Manufacturers' credit                                     277,000            276,000
        Capitalized research expenses                                         40,000             21,000
        Other                                                                738,000          1,476,000
                                                                         -----------        -----------
                Total deferred tax assets                                  2,769,000          4,047,000
      Deferred tax liability:
        Tax over book depreciation                                          (121,000)           (21,000)
                                                                         -----------        -----------
      Net deferred tax assets                                            $ 2,648,000        $ 4,026,000
                                                                         -----------        -----------
                                                                         -----------        -----------
</TABLE>

                                      F-16

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

    No valuation has been recorded to offset the deferred tax assets as the
Company has determined that it is more likely than not that such assets will be
realized. As of December 31, 1998, the Company has approximately $4.0 million of
net deferred tax assets, with no offsetting valuation allowance as realization
of such assets has been assessed by the Company as more likely than not. The
realization of the deferred tax assets is dependent upon the generation of
future taxable income of approximately $10 million. The Company will continue to
assess the likelihood of realization of such assets; however, if future events
occur which do not make the realization of such assets more likely than not, the
Company will record a valuation allowance against all or a portion of the net
deferred tax assets.

    The reconciliation of income tax computed at the federal statutory tax rate
to the benefit (provision) for income taxes is as follows:

<TABLE>
<CAPTION>
                                                                                           December 31,
                                                                                 1996          1997          1998
                                                                              ----------    ----------    ----------
      <S>                                                                     <C>           <C>           <C>
      Tax at federal statutory rate                                               35%           35%            35%
      Permanent tax differences                                                    2            (2)            (5)
      Decrease in valuation allowance for deferred tax assets                    (29)            -              -
      Tax credits                                                                  -           (30)            31
      Other                                                                       (1)            3             (4)
                                                                                ------        ------        ------
      Effective rate                                                               7%            6%            57%
                                                                                ------        ------        ------
                                                                                ------        ------        ------
</TABLE>

    Pursuant to Internal Revenue Code Section 382, use of the Company's tax
credit carryforwards may be limited if a cumulative change in ownership of more
than 50% occurs within any three year period. However, any annual limitation is
not expected to have a material adverse effect on the Company's ability to
utilize its tax credit carryforwards.

9. Employee Savings Plan

    In 1991, the Company implemented a 401(k) program which allows all
qualifying employees to contribute up to a maximum of 20% of their annual
salary, subject to annual limits. The Board of Directors may, at its sole
discretion, approve Company contributions. No such contributions have been
approved or made.

10. Defense of Patent Matters

In September 1997, Behring Diagnostics, Inc. and Behring Diagnostics, GmbH filed
a patent infringement action against the Company in the U.S. District Court for
the District of Delaware. The patent infringement action alleged that the
Company's Triage DOA Panel products infringed a patent held by the plaintiffs,
which expires in August 2000. The plaintiffs sought to recover damages of an
unspecified amount and to enjoin future sales of the Triage DOA Panel products
by the Company. Biosite answered the complaint, denying infringement and
asserting affirmative defenses that the patent is invalid and unenforceable.
Because of a merger, the identity of the plaintiffs changed to Dade Behring
Inc., Dade Behring Marburg GmbH and Syva Company (collectively "Dade Behring").
To avoid protracted litigation and continued significant legal defense costs,
the Company and Dade Behring executed a settlement agreement in March 1999 that
resolved all disputes outstanding between the companies. Under the terms of the
settlement agreement, the Company obtained a license to the patent and will
provide Dade Behring the option to evaluate certain proprietary antibodies,
resulting in a net payment of $1,050,000 to Dade Behring by Biosite. The Company
has charged to defense of patent matters in the accompanying statements of
income the applicable license costs related to years prior to 1998 of $604,000.

                                      F-17

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

    On April 28, 1998, Spectral Diagnostics, Inc. ("Spectral") filed a patent
infringement action against the Company in the U.S. District Court for the
Western District of Wisconsin, alleging that the Company's Triage Cardiac Panel
infringes U.S. patent 5,744,358 which was issued on the date the suit was filed.
Spectral sought a permanent injunction and damages. Spectral also sought a
preliminary injunction that would enjoin the Company from selling the Triage
Cardiac Panel. On July 16, 1998, the Court issued an opinion denying the motion
for a preliminary injunction. Spectral also moved for partial summary judgment
on the issue of infringement. That motion was denied on July 20, 1998. The
established trial date of August 31, 1998 was set aside while the two companies
engaged in negotiations in an attempt to arrive at a settlement in regards to
all disputes outstanding between Biosite and Spectral. In February 1999, a
settlement agreement was executed that resolved all disputes between the
companies without a material adverse financial impact to Biosite.

    In September 1996, the Company reached a settlement with a competitor with
respect to all claims in a lawsuit filed by the competitor in May 1994. The
complaint alleged that the Company's Triage Panel for Drugs of Abuse product
infringed a patent licensed to the competitor. The Company vigorously defended
the lawsuit. However, to avoid protracted litigation, the Company settled the
patent matter in September 1996, and paid $2.0 million as a settlement of the
litigation and, for an additional $3.5 million and the agreement to pay certain
royalties, obtained a license to certain technology. The Company has charged to
defense of patent matters in the accompanying statements of income the $2.0
million litigation settlement, applicable license costs related to years prior
to 1996 and the related legal defense costs.

    Legal defense costs were approximately $17,000, $331,000, and $4,257,000 for
the years ended December 31, 1996, 1997 and 1998, respectively.

                                      F-18

<PAGE>

                        BIOSITE DIAGNOSTICS INCORPORATED

                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)

11. Quarterly Information (Unaudited)

The following quarterly information includes all adjustments which management
considers necessary for a fair statement of such information. For interim
quarterly financial statement, the provision for income taxes is estimated using
the best available information for projected results for the entire year

<TABLE>
<CAPTION>
                                                                                            1997
                                                                       FIRST         SECOND        THIRD         FOURTH
                                                                      QUARTER       QUARTER       QUARTER       QUARTER
                                                                   -------------- ------------- ------------- -------------
                                                                            (in thousands, except per share data)
<S>                                                                <C>            <C>             <C>         <C>
Net Sales                                                           $  7,533       $  7,797       $  8,079    $   8,268
Gross Profit                                                           5,909          6,184          6,385        6,273
Income (loss) before income taxes                                      1,527          1,533          1,155       (2,935)
Net Income (Loss)                                                        992            986            889       (1,669)

Net income (loss) per share
  - Basic                                                           $   0.15       $   0.08       $   0.07    $   (0.13)
  - Diluted                                                         $   0.08       $   0.07       $   0.07    $   (0.13)

Shares used in calculating per share amounts
  - Basic                                                              6,621         12,750         12,803       12,820
  - Diluted                                                           11,886         13,440         13,454       12,820
</TABLE>

<TABLE>
<CAPTION>
                                                                                             1998
                                                                       FIRST         SECOND        THIRD         FOURTH
                                                                      QUARTER       QUARTER       QUARTER       QUARTER
                                                                   -------------- ------------- ------------- -------------
                                                                            (in thousands, except per share data)
<S>                                                                <C>            <C>             <C>         <C>
Net sales                                                           $  7,884       $  8,711       $  8,752    $   9,077
Gross profit                                                           6,129          6,368          5,715        5,699
Income (loss) before income taxes                                       (724)          (310)           219       (1,745)
Net income (loss)                                                       (500)          (374)           455         (693)

Net income (loss) per share
  - Basic                                                           $  (0.04)      $  (0.03)      $   0.04    $   (0.05)
  - Diluted                                                         $  (0.04)      $  (0.03)      $   0.03    $   (0.05)

Shares used in calculating per share amounts
  - Basic                                                             12,906         12,938         12,986       12,923
  - Diluted                                                           12,906         12,938         13,514       12,923
</TABLE>

                                      F-19

<PAGE>

                                   SCHEDULE II

                        BIOSITE DIAGNOSTICS INCORPORATED

                        VALUATION AND QUALIFYING ACCOUNTS

<TABLE>
<CAPTION>
- --------------------------------------------- ------------------ ---------------------------------- ------------- -------------
                      COL. A                       COL. B                         COL. C             COL. D          COL. E
- --------------------------------------------- ------------------ ---------------------------------- ------------- -------------
                                                                                Additions
- --------------------------------------------- ------------------ ---------------------------------- ------------- -------------
                                                                                    Charged to
                                                 Balance at      Charged to Costs      Other                        Balance at
                    Description                 Beginning of       and Expenses      Accounts-      Deductions -      End of
                                                   Period                             Describe       Describe         Period
- --------------------------------------------- ------------------ ----------------- ---------------- ------------- -------------
<S>                                           <C>                <C>               <C>              <C>           <C>       
Year ended December 31, 1998                                     
Allowance for doubtful accounts                  $  13,721         $   4,311             $ -        $      -         $  18,032
Reserve for obsolete or excess inventory         $ 304,860         $ 540,662             $ -        $ 46,878 (2)     $ 798,644


Year ended December 31, 1997
Allowance for doubtful accounts                  $   4,405         $  19,555             $ -        $ 10,239 (1)     $  13,721
Reserve for obsolete or excess inventory         $ 193,736         $ 119,230             $ -        $  8,106 (2)     $ 304,860

Year ended December 31, 1996
Allowance for doubtful accounts                  $       -         $   4,405             $ -        $        -       $   4,405
Reserve for obsolete or excess inventory         $ 213,322         $ (18,026) (3)        $ -        $  1,560 (2)     $ 193,736

</TABLE>

(1)   Uncollectible accounts written off, net of recoveries
(2)   Write off of obsolete or excess inventory
(3)   Reduction for revised estimate of reserve for excess inventory due to
      growth in sales forecast and composition of inventory

<PAGE>

                                                                  EXHIBIT 23.1



               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS


We consent to the incorporation by reference in the Registration Statements 
Forms S-8 Nos. 333-17657 and 333-59701 pertaining to the Employee Stock 
Purchase Plan and Nos. 333-26763 and 333-59705 pertaining to the amended and 
restated 1996 Stock Incentive Plan, of Biosite Diagnostics Incorporated of 
our report dated February 11, 1999, except for Note 10, as to which the date 
is March 29, 1999, with respect to the financial statements and schedule of 
Biosite Diagnostics, Inc. included in the Annual Report (Form 10-K) for the 
year ended December 31, 1998.

                                       ERNST & YOUNG LLP

San Diego, California
March 29, 1999

<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REGISTRANTS FINANCIAL STATEMENTS AS OF AND FOR THE YEAR END DECEMBER 31, 1998
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS
INCLUEDED IN THE COMPANY'S 1998 ANNUAL REPORT ON FORM 10-K.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               DEC-31-1998
<CASH>                                             762
<SECURITIES>                                    33,467
<RECEIVABLES>                                    6,574
<ALLOWANCES>                                         0
<INVENTORY>                                      4,364
<CURRENT-ASSETS>                                48,301
<PP&E>                                          17,149
<DEPRECIATION>                                   9,835
<TOTAL-ASSETS>                                  65,809
<CURRENT-LIABILITIES>                            7,087
<BONDS>                                          4,038
                                0
                                          0
<COMMON>                                           129
<OTHER-SE>                                      54,554
<TOTAL-LIABILITY-AND-EQUITY>                    54,683
<SALES>                                         34,424
<TOTAL-REVENUES>                                39,450
<CGS>                                           10,514
<TOTAL-COSTS>                                   31,497
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                (2,561)
<INCOME-TAX>                                     1,448
<INCOME-CONTINUING>                            (1,113)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (1,113)
<EPS-PRIMARY>                                   (0.09)<F1>
<EPS-DILUTED>                                   (0.09)
<FN>
<F1>EARNINGS PER SHARE IS CALCULATED ON THE BASIS DESCRIBED IN NOTE 1 OF NOTES TO
FINANCIAL STATEMENTS.
</FN>
        

</TABLE>


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