ONCOR INC, S-3/A, 1998-08-20

ONCOR INC
S-3/A, 1998-08-20
IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES

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<PAGE> 1

AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 20, 1998
REGISTRATION NO. 333-46855

================================================================================
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

------------------
AMENDMENT NO. 3

TO
FORM S-3
REGISTRATION STATEMENT
UNDER THE SECURITIES ACT OF 1933
------------------
ONCOR, INC.
(Exact name of Registrant as specified in its charter)
------------------
<TABLE>
<S> <C>
MARYLAND 52-1310084
(State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification Number)
</TABLE>

209 PERRY PARKWAY, GAITHERSBURG, MARYLAND 20877
(301) 963-3500
(Address, including zip code, and telephone number,
including area code, of Registrant's principal executive offices)
------------------
CECIL KOST
PRESIDENT AND CHIEF OPERATING OFFICER
ONCOR, INC.
209 PERRY PARKWAY
GAITHERSBURG, MARYLAND 20877
(301) 963-3500
(Name, address, including zip code, and telephone number,
including area code, of agent for service of process)

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

COPIES TO:
RICHARD R. PLUMRIDGE, ESQ.
BRIAN B. MARGOLIS, ESQ.
BROBECK, PHLEGER & HARRISON LLP
1633 BROADWAY, 47TH FLOOR
NEW YORK, NEW YORK 10019
(212) 581-1600

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As
soon as practicable on or after this Registration Statement is declared
effective.

If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. [ ]

If any of the securities being registered on this Form are to be
offered on a delayed or continuous basis pursuant to Rule 415 under the
Securities Act of 1933, other than securities offered only in connection with
dividend or interest reinvestment plans, check the following box. [X]

If this Form is filed to register additional securities for an
offering pursuant to Rule 462(b) under the Securities Act, please check the
following box and list the Securities Act registration statement number of the
earlier effective registration statement for the same offering. [ ]

If this Form is a post-effective amendment filed pursuant to Rule
462(c) under the Securities Act, check the following box and list the
Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]

If delivery of the prospectus is expected to be made pursuant to Rule
434, please check the following box. [ ]

CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
==================================================================================================================================
TITLE OF SHARES AMOUNT TO BE PROPOSED MAXIMUM PROPOSED MAXIMUM AGGREGATE AMOUNT OF
TO BE REGISTERED REGISTERED AGGREGATE PRICE PER UNIT(1) OFFERING PRICE(1) REGISTRATION FEE
- ----------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C>
Common Stock,
$.01 par value 5,587,965 Shares $0.40625 $2,270,110.70 $669.69(2)
==================================================================================================================================
</TABLE>

(1) Based upon the average of the high and low prices of the Common Stock,
as reported on the American Stock Exchange, on August 19, 1998.

(2) Previously paid.

------------------
THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES
AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL FILE
A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT
SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF THE
SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
================================================================================
<PAGE> 2
PROSPECTUS
5,587,965 SHARES
ONCOR, INC.
COMMON STOCK

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

This Prospectus relates to the offer and sale, which is not being
underwritten, by certain persons listed herein under "Selling Stockholders"
(collectively, the "Selling Stockholders"), of up to 5,587,965 shares (the
"Shares") of Common Stock, par value $.01 per share, of Oncor, Inc. ("Oncor" or
the "Company"). The Shares are issuable by the Company to the Selling
Stockholders (i) upon the conversion of the Series A Preferred Stock and (ii)
upon exercise of the Warrants. The Shares may be offered by holders of the
Series A Preferred Stock who convert their Series A Preferred Stock and the
holders of the Warrants who subsequently exercise their Warrants.

The Shares may be offered by the Selling Stockholders from time to
time in transactions on the American Stock Exchange, in negotiated
transactions, or a combination of such methods of sale, at fixed prices which
may be changed, at market prices prevailing at the time of sale, at prices
related to prevailing market prices or at negotiated prices. The Selling
Stockholders may effect such transactions by selling the Shares to or through
broker-dealers, and such broker-dealers may receive compensation in the form of
discounts, concessions or commissions from the Selling Stockholders and/or the
purchasers of the Shares for whom such broker-dealers may act as agents or to
whom they sell as principals, or both (which compensation as to a particular
broker-dealer might be in excess of customary commissions). In order to comply
with the securities laws of certain states, if applicable, the Shares will be
sold in such jurisdictions only through registered or licensed brokers or
dealers. The Selling Stockholders may transfer their Series A Preferred Stock
or Warrants under certain circumstances to other persons who may, in turn,
resell Shares in the manner described above. In addition, the Selling
Stockholders may pledge or make gifts of their Shares and such Shares may also
be sold by the pledgees or transferees. To the extent required, the specific
Shares to be sold, the names of the Selling Stockholders, the public offering
price, the names of any such agent, dealer or underwriter, and any applicable
commission or discount with respect to any particular offer will be set forth
in an accompanying Prospectus Supplement. See "Selling Stockholders" and "Plan
of Distribution."

None of the proceeds from the sale of the shares issued upon
conversion of the Series A Preferred Stock (the "Series A Shares") by the
Selling Stockholders will be received by the Company. The Company will receive
aggregate proceeds of up to $644,500 upon the exercise of the Warrants
outstanding as of the date of this Prospectus, but will not receive any
proceeds from the subsequent sale of the shares issued upon exercise of the
Warrants (the "Warrant Shares"). See "Issuance of the Shares and Use of
Proceeds." The Company has agreed to bear certain expenses (other than
underwriting discounts and selling commissions and fees and disbursements of
counsel and other advisors to the Selling Stockholders) in connection with the
registration of the Shares. The Company has agreed to indemnify the Selling
Stockholders and their affiliates against certain liabilities, including
liabilities under the Securities Act of 1933, as amended (the "Securities
Act"). The Company and the Selling Stockholders have agreed to indemnify each
other against certain liabilities, including liabilities under the Securities
Act under certain circumstances.

The Common Stock of the Company is traded on the American Stock
Exchange under the symbol "ONC." The last reported sales price of the Company's
Common Stock on the American Stock Exchange on August 19, 1998 was $0.4375 per
share.

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

AN INVESTMENT IN THE SHARES OFFERED HEREBY INVOLVES A HIGH DEGREE OF RISK.
SEE "RISK FACTORS" BEGINNING ON PAGE 4.

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

THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS
PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.

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

THE DATE OF THIS PROSPECTUS IS AUGUST 20, 1998

<PAGE> 3
NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS IN CONNECTION
WITH THE OFFERING MADE HEREBY, AND IF GIVEN OR MADE, SUCH INFORMATION OR
REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED BY THE
COMPANY, ANY SELLING STOCKHOLDER OR BY ANY OTHER PERSON. THIS PROSPECTUS DOES
NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF AN OFFER TO BUY THE SHARES
TO ANY PERSON OR BY ANYONE IN ANY JURISDICTION IN WHICH SUCH OFFER OR
SOLICITATION MAY NOT LAWFULLY BE MADE. NEITHER THE DELIVERY OF THIS PROSPECTUS
NOR ANY SALE MADE HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY
IMPLICATION THAT THE INFORMATION HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO
THE DATE HEREOF.

TABLE OF CONTENTS
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PAGE
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<S> <C>
Available Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Incorporation of Certain Documents by Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
The Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Issuance of the Shares and Use of Proceeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Selling Stockholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Plan of Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Legal Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Experts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
</TABLE>

AVAILABLE INFORMATION

The Company has filed with the Securities and Exchange Commission (the
"Commission") a Registration Statement on Form S-3 under the Securities Act
with respect to the Common Stock offered hereby. This Prospectus does not
contain all of the information set forth in the Registration Statement and the
exhibits and the schedules thereto. For further information with respect to
the Company and such Common Stock, reference is made to the Registration
Statement and exhibits and schedules thereto. Statements contained in this
Prospectus as to the contents of any contract or other document referred to are
not necessarily complete, and, with respect to any contract or other document
filed as an exhibit to the Registration Statement, each such statement is
qualified in all respects by reference to such exhibit. Copies of the
Registration Statement and the exhibits thereto are on file at the offices of
the Commission and may be obtained upon payment of the prescribed fee or may be
examined without charge at the public reference facilities of the Commission
described below.

The Company is subject to the reporting requirements of the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), and in accordance
therewith files annual and quarterly reports, proxy statements and other
information with the Commission. Such reports, proxy statements and other
information may be inspected, and copies of such material may be obtained upon
payment of the prescribed fees, at the Commission's Public Reference Section,
Room 1024, 450 Fifth Street, N.W., Washington D.C. 20549, as well as at the
Commission's Regional Offices at Seven World Trade Center, New York, New York
10048, and Citicorp Center, 500 West Madison Street, Suite 1400, Chicago,
Illinois 60661-2511, or may be obtained from the Commission's Internet site on
the world wide web at http://www.sec.gov. Copies of such material can be
obtained in person from the Public Reference Section of the Commission at its
principal office located at 450 Fifth Street, N.W., Washington, D.C. 20549,
upon payment of the prescribed fees.

The Common Stock of the Company is traded on the American Stock
Exchange, and in accordance therewith, annual and quarterly reports, proxy
statements and other information concerning the Company may be inspected at the
American Stock Exchange's offices located in New York.

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<PAGE> 4
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The following documents filed with the Commission are hereby
incorporated by reference in this Prospectus: (1) the Annual Report of the
Company on Form 10-K for the fiscal year ended December 31, 1997 (the "1997 Form
10-K"), as amended by Amendment No. 1 to the 1997 Form 10-K; (2) the Quarterly
Report of the Company on Form 10-Q for the three months ended March 31, 1998
(the "First Quarter Form 10-Q"), as amended by Amendment No. 1 to the First
Quarter Form 10-Q; (3) the Quarterly Report of the Company on Form 10-Q for the
three months ended June 30, 1998; (4) the Proxy Statement of the Company in
connection with the Annual Meeting of the Stockholders held on June 25, 1998;
(5) the Current Report of the Company on Form 8-K, dated January 16, 1998; and
(6) the Current Report of the Company on Form 8-K, dated July 7, 1998.

All reports and other documents subsequently filed by the Company
pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the
date of this Prospectus and prior to the termination of this Offering shall be
deemed to be incorporated by reference herein and to be a part hereof from the
date of filing of such reports and documents. Any statement incorporated
herein shall be deemed to be modified or superseded for purposes of this
Prospectus to the extent that a statement contained herein or in any other
subsequently filed document which also is or is deemed to be incorporated by
reference herein modifies or supersedes such statement. Any statement so
modified or superseded shall not be deemed, except as so modified or
superseded, to constitute a part of this Prospectus.

The Company will provide without charge to each person to whom this
Prospectus is delivered, upon written or oral request of such person, a copy of
any or all of the foregoing documents incorporated herein by reference (other
than exhibits to such documents, unless such exhibits are specifically
incorporated by reference into such document). Requests for such documents
should be submitted in writing to Mr. John L. Coker, Vice President, Oncor,
Inc., 209 Perry Parkway, Gaithersburg, Maryland 20877.

DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS

THIS PROSPECTUS INCLUDES "FORWARD-LOOKING STATEMENTS" WITHIN THE MEANING OF
SECTION 27A OF THE SECURITIES ACT AND SECTION 21E OF THE SECURITIES EXCHANGE
ACT OF 1934, AS AMENDED (THE "EXCHANGE ACT"). ALL STATEMENTS OTHER THAN
STATEMENTS OF HISTORICAL FACTS INCLUDED IN THIS PROSPECTUS OR INCORPORATED
HEREIN BY REFERENCE REGARDING THE COMPANY'S FINANCIAL POSITION AND BUSINESS
STRATEGY MAY CONSTITUTE FORWARD-LOOKING STATEMENTS. ALTHOUGH THE COMPANY
BELIEVES THAT THE EXPECTATIONS REFLECTED IN SUCH FORWARD-LOOKING STATEMENTS ARE
REASONABLE, IT CAN GIVE NO ASSURANCE THAT SUCH EXPECTATIONS WILL PROVE TO HAVE
BEEN CORRECT. IMPORTANT FACTORS THAT COULD CAUSE ACTUAL RESULTS TO DIFFER
MATERIALLY FROM THE COMPANY'S EXPECTATIONS ("CAUTIONARY STATEMENTS") ARE
DISCLOSED IN THIS PROSPECTUS, INCLUDING WITHOUT LIMITATION, IN CONJUNCTION WITH
THE FORWARD-LOOKING STATEMENTS UNDER "RISK FACTORS." ALL SUBSEQUENT WRITTEN
AND ORAL FORWARD-LOOKING STATEMENTS ATTRIBUTABLE TO THE COMPANY OR PERSONS
ACTING ON ITS BEHALF ARE EXPRESSLY QUALIFIED IN THEIR ENTIRETY BY THE
CAUTIONARY STATEMENTS

THE COMPANY

The Company was incorporated in Maryland in July 1983. The Company's
principal offices are located at 209 Perry Parkway, Gaithersburg, Maryland
20877, and its telephone number is (301) 963-3500.

- 3 -
<PAGE> 5
RISK FACTORS

An investment in the shares of Common Stock offered hereby involves a
high degree of risk and should not be made by any investor who cannot afford
the loss of his entire investment. Accordingly, prospective investors should
carefully consider the following factors, in addition to all of the other
information presented in this Prospectus, before purchasing any of the shares
of Common Stock offered hereby.

HISTORY OF OPERATING LOSSES

Oncor has not been profitable since its inception in July 1983. For
the quarter ended June 30, 1998, the Company incurred net losses of
approximately $2.4 million and as of that date, the accumulated deficit of the
Company was $148 million. The Company expects to incur additional losses in
future periods. The Company believes it will become profitable sometime in 1999
but cannot provide assurance as to when, if ever, it will achieve
profitability.

ADDITIONAL FINANCING REQUIREMENTS AND ACCESS TO CAPITAL FUNDING

The Company expects that its current liquid resources will not be
sufficient to fund operations after the end of September 1998. Funds, if any,
raised from most of the possible sources during the intervening period may
first be utilized to repay, in whole or in part, the Company's bank debt of
$4.0 million in accordance with the terms of the underlying line of credit and
related guarantees. The line of credit, which expires on October 31, 1998, is
guaranteed by certain shareholders whose guarantees are secured by
substantially all of the assets of the Company.

The Company is considering additional alternative forms of financing,
including among other things, equity or debt financing, sale of publicly-traded
Oncormed common stock, recovery of Oncor advances to Codon, sale of Appligene
stock and other alternatives.

There can be no assurance that any of the alternatives discussed
above, or any other such forms of financing, can be completed by the Company in
sufficient amounts, in timely fashion, on acceptable terms, or at all, which
would have a material adverse effect on the Company. Even if completed, each of
such financing alternatives may have certain terms, conditions or ramifications
which may have a material adverse effect on the Company's business, financial
condition and results of operations. For instance, any such equity financings
likely will be dilutive to stock holders, the terms of any debt financing, as
does the existing line of credit, may require substantially all of the assets
of the Company to be pledged as collateral, may involve warrant or equity
dilution and/or may contain restrictive covenants which limit the Company's
ability to pursue certain courses of action, and the sale of assets will
decrease the revenue base of the Company.

While the Company is using its best efforts to consummate one or more
of these potential sources of funding, it is possible that the success, if any,
of these efforts will not be sufficient to fund the Company for the foreseeable
future. The Company has taken, and is continuing to take, substantial cost-
cutting actions, including significant reductions in its number of employees.
In the event that the Company is unable to raise additional capital by the end
of September 1998, the Company may promptly cease significant portions of its
programs, projects and business operations. If the pursuit of these potential
funding sources proves largely unsuccessful, the Company may be forced into the
complete termination of its business operations.

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<PAGE> 6

NO ASSURANCE OF CONTINUED LISTING OF COMMON STOCK

Due to its history of losses and other related factors, the Company
continues to be below certain guidelines for continuing listing of its common
stock on its principal exchange, the American Stock Exchange (the "Exchange").
The Exchange has the authority to invoke or waive the guidelines at its sole
discretion. In July 1998, the Exchange requested, and the Company agreed that it
will provide the Exchange with, certain financial information and projections in
support of continued listing. There can be no assurance that this information
will be satisfactory to the Exchange and that the Company's stock will continue
to be listed on the Exchange. If the Company's stock were delisted from the
Exchange, any alternative public markets or exchanges that may be available to
the Company likely would provide substantially less liquidity and market support
for the shareholders of the Company and materially and adversely affect the
ability, if any, of the Company to raise additional equity capital in the
future.

REQUESTED REDEMPTION OF SERIES A CONVERTIBLE PREFERRED STOCK

On August 7, 1998 and August 11, 1998, the Company received requests
from the holders of its Series A Convertible Preferred Stock (the "Preferred
Stock"), which had an aggregate original issuance amount equal to $5.0 million,
to have their shares of Preferred Stock redeemed. As of August 13, 1998, none of
the holders of Preferred Stock had completed all of the steps necessary for
redemption. In any event, the Company believes that the holders of the Preferred
Stock have not tendered a valid redemption request and, therefore, at this time,
the Company does not believe it is required to comply with the requested
redemption. There can be no assurance that such redemption request will
ultimately be found to be invalid. In the event that such redemption request is
ultimately held to be valid, and the Company is unable to obtain the funds
necessary to redeem the Preferred Stock, the non-payment of such redemption
amounts would have a material and adverse effect on the Company's business,
results of operations and financial condition.

RECENT DISPOSITION OF NON-STRATEGIC ASSETS

The Company has recently completed the sale or other conveyance of
its two non-strategic asset groups: the research products assets and the
non-oncology genetic probe systems assets. As a result, the scope of the
Company's business (including its revenue base) and its number of products
has been reduced significantly. The Company's few remaining products presently
marketed to North America are cancer-related genetic probe tests, including the
INFORM(TM) HER-2/neu diagnostic test, which currently is sold to a limited
number of customers. The disposal of each of these asset groups has resulted in
a significant decrease in the number of employees in the Company and in the
number of patents and trademarks owned by the Company. There can be no
assurance that the disposition of these two business units will not have a
material adverse effect on the business, financial condition and results of
operations of the Company. See "Business -- Recent Developments."

RISK ASSOCIATED WITH THE INFORM(TM) HER-2/NEU GENE-BASED TEST
SYSTEM

Although the PMA for the Oncor INFORM(TM) HER-2/neu Gene Detection
System was approved for marketing by the U.S. Food and Drug Administration (the
"FDA") in December 1997, there can be no assurance that the Company will be
capable of manufacturing the test system in commercial quantities at reasonable
costs or marketing the product successfully, that the test system will be
accepted by the medical diagnostic community, or that the market demand for the
test system will be sufficient to allow profitable sales. In addition, product
approvals may be withdrawn if compliance with regulatory standards is not
maintained or if substantial problems occur after the product reaches the
market.

NO ASSURANCE OF REGULATORY APPROVALS; GOVERNMENT REGULATION

The Company expects to pursue FDA approval or clearance of certain
existing products and products under development. There can be no assurance that
the Company will receive regulatory approval or clearance for any of its
products currently under development or, even if it does receive regulatory
approval or clearance for a particular product, that the Company will ever
recover its costs in connection with obtaining such approval or clearance. The
timing of regulatory decisions is not within the control of the Company. The
failure of the Company to receive requisite approval or clearance, or
significant delays in obtaining such approval or clearance, could have a
material and adverse effect on the business, financial condition and results of
operations of the Company.

Approval or clearance by the FDA require lengthy, detailed and
costly laboratory procedures, clinical testing procedures and application
preparation and defense efforts to demonstrate a product's efficacy and safety
(or equivalence to a marketed product in the case of a 510(k) submission) before
a product can be sold for diagnostic use. Even if such regulatory approval or
clearance is obtained for a product, its manufacturer and its manufacturing
facilities are subject to continual review and periodic inspections by the FDA
and other regulatory agencies. The regulatory standards for manufacturing are
applied stringently by the FDA. Discovery of previously unknown problems with a
product, manufacturer or facility may result

<PAGE> 7

in restrictions on such product or manufacturer, including costly recalls or
even withdrawal of the product from the market. Furthermore, approval may entail
ongoing requirements for postmarketing studies. Failure to maintain requisite
manufacturing standards or discovery of previously unknown problems could have a
material and adverse effect on the Company's business, financial condition or
results of operations.

PATENTS AND PROPRIETARY RIGHTS

The Company's success will depend in large part on its, and its
licensors', ability to obtain patents, defend their patents, maintain trade
secrets and operate without infringing upon the proprietary rights of others,
both in the United States and in foreign countries. The patent position of firms
relying upon biotechnology is highly uncertain in general and involves complex
legal and factual questions. To date there has emerged no consistent policy
from the courts regarding the breadth of claims allowed in biotechnology patents
or the degree of protection afforded under such patents. The Company relies on
certain patents and pending U.S. and foreign patent applications relating to
various aspects of its products. These patents and patent applications are
either owned by the Company or rights under them are licensed to the Company.
There can be no assurance that patents will issue as a result of any such
pending applications or that, if issued, such patents will be sufficiently broad
to afford protection against competitors with similar technology. In addition,
there can be no assurance that any patents issued to the Company, or for which
the Company has license rights, will not be challenged, invalidated or
circumvented, or that the rights granted thereunder will provide competitive
advantages to the Company.

The University of California and its licensee, Vysis, Inc.
("Vysis"), filed suit against Oncor on September 5, 1995 for infringement of
U.S. Patent No. 5,447,841 entitled Methods and Compositions for Chromosome
Specific Staining which issued on that same date. The patent relates to a method
of performing in situ hybridization using a blocking nucleic acid that is
complementary to repetitive sequences. On April 9, 1998, the Company, Vysis and
the University of California entered into a definitive agreement to settle the
litigation. In connection with the settlement, the Company obtained certain
non-exclusive royalty bearing licenses,

<PAGE> 8

made an initial payment of $0.5 million to Vysis, and an additional payment
of $1.5 million will be due on April 10, 2000 in order to extend the licenses
beyond that date.

The commercial success of the Company will also depend upon avoiding
the infringement of patents issued to competitors and upon maintaining the
technology licenses upon which certain of the Company's current products are, or
any future products under development might be, based. Litigation, which could
result in substantial cost to the Company, may be necessary to enforce the
Company's patent and license rights or to determine the scope and validity of
others' proprietary rights. If competitors of the Company prepare and file
patent applications in the United States that claim technology also claimed by
the Company, the Company may have to participate in interference proceedings
declared by the Patent and Trademark Office (the "PTO") to determine the
priority of invention, which could result in substantial cost to the Company,
even if the outcome is favorable to the Company. An adverse outcome could
subject the Company to significant liabilities to third parties and require the
Company to license disputed rights from third parties or cease using the
technology. A U.S. patent application is maintained under conditions of
confidentiality while the application is pending in the PTO, so that the Company
cannot determine the inventions being claimed in pending patent applications
filed by its competitors in the PTO. Further, U.S. patents do not provide any
remedies for infringement that occurred before the patent is granted.

On April 27, 1998, the Company received a summons and complaint in
connection with a lawsuit entitled Key Technology, Inc. v. Oncor, Inc. in the
Superior Court of the State of Washington for the County of Walla Walla. The
complaint alleges breach of contract and fraud in connection with a June 1996
asset purchase agreement between Key Technology and the Company relating to the
sale of the Company's I300 video inspection system to Key Technology, and seeks
damages against the Company of $1.5 million. A failure to successfully defend
against or settle that suit would likely result in damages being assessed
against the Company and could have a material adverse effect on the Company's
financial condition or results of operations.

On May 29, 1998, a complaint was filed against the Company in the
U.S. District Court for the Eastern District of New York by Paul Diamond,
alleging that the Company is infringing his U.S. Patent No. 5,597,697 by
making, using and selling its SUNRISE(TM) DNA amplification detection system.
While the Company believes that the action, which was filed pro se (without the
assistance of counsel), is without merit, patent litigation is generally costly
and the disposition or outcome of this case cannot be predicted with certainty.

The Company currently has certain licenses from third parties and in
the future may require additional licenses from other parties to develop,
manufacture and market commercially viable products effectively. There can be no
assurance that such licenses will be obtainable on commercially reasonable
terms, if at all, that the patents underlying such licenses will be valid and
enforceable or that the proprietary nature of the patented technology underlying
such licenses will remain proprietary.

<PAGE> 9

The Company relies substantially on certain technologies that are
not patentable or proprietary and are therefore available to the Company's
competitors. The Company also relies on certain proprietary trade secrets and
know-how that are not patentable. Although the Company has taken steps to
protect its unpatented trade secrets and know-how, in part through the use of
confidentiality agreements with its employees, consultants and certain of its
contractors, there can be no assurance that these agreements will not be
breached, that the Company would have adequate remedies for any breach, or that
the Company's trade secrets will not otherwise become known or be independently
developed or discovered by competitors.

UNCERTAINTIES RELATING TO PRODUCT DEVELOPMENT

The Company's actively marketed products other than the INFORM(TM)
HER-2/neu Gene Detection System have not been approved by the FDA and may be
sold only for research purposes in the United States and certain other
countries. The Company has undertaken to seek FDA approval for certain of these
products, and may in the future undertake to seek such approval or clearance for
other products, and substantial additional investment, laboratory development,
clinical testing, controlled manufacturing and FDA approval or clearance will be
required prior to the commercialization of such products for diagnostic
purposes. There can be no assurance that the Company will be successful in
developing such existing or future products, that such products will prove to be
efficacious in clinical trials, that required regulatory approvals or clearances
can be obtained for such products, that such products, if developed and
approved, will be capable of being manufactured in commercial quantities at
reasonable costs, will be marketed successfully or will be accepted by the
medical diagnostic community, or that market demand for such products will be
sufficient to allow profitable operations.

INTERNATIONAL SALES AND FOREIGN EXCHANGE RISK

The Company anticipates that a significant amount of its sales will
take place in European countries and Japan and likely will be denominated in
currencies other than the U.S. dollar. These sales may be adversely affected by
changing economic conditions in foreign countries and by fluctuations in
currency exchange rates. Any significant decline in the applicable rates of
exchange could have a material adverse effect on the Company's business,
financial condition and results of operations. Additional risks inherent in the
Company's international business activities generally include unexpected changes
in regulatory requirements, tariffs and other trade barriers, lack of acceptance
of products in foreign markets, longer accounts receivable payment cycles,
difficulties in managing international operations, potentially adverse tax
consequences, restrictions on repatriation of earnings and the burdens of
complying with a wide variety of foreign laws. There can be no assurance that
such factors will not have a material adverse effect on the Company's future
international revenues and, consequently, on the Company's business, financial
condition and results of operations.

<PAGE> 10

LIMITED MANUFACTURING EXPERIENCE

The Company's ability to conduct clinical trials on a timely basis,
to obtain regulatory approvals or clearances and to commercialize its products
will depend in part upon its ability to develop and maintain facilities to
manufacture its products, either directly or through third parties, at a
competitive cost in accordance with the FDA's prescribed current GMP and other
regulatory requirements. Any failure to maintain manufacturing facilities in
accordance with the FDA's GMP requirements could result in the inability of the
Company to manufacture its products and may limit the Company's ability to
deliver its products to its customers, which would have a material and adverse
effect on the Company's business, financial condition and results of operations.
No assurance can be given that the Company will be able to develop and maintain
GMP facilities or engage third parties to do so at a cost acceptable to the
Company.

The Company has only limited experience in manufacturing products on
a commercial basis. The Company believes that its existing manufacturing
facilities, along with available contiguous space currently under option to the
Company, will enable it to produce commercial quantities of its products
through at least 1998. No assurance can be given, however, that manufacturing or
quality control problems will not arise if the Company increases production of
its products, or if additional facilities are required in the future.

LIMITED MARKETING AND DISTRIBUTION EXPERIENCE

The Company markets and sells its products for research purposes
and, once approved or cleared by the appropriate regulatory authority, for
diagnostic use, through its direct sales forces in both Europe and the United
States and indirectly through third parties in the Pacific Rim and other areas.
The Company only has limited experience in sales, marketing, training and
distribution. In order to market its products directly, the Company must
maintain a sales force with technical expertise and an understanding of the
Company's products. There can be no assurance that the Company will be able to
maintain such a sales force or that the Company's direct sales and marketing
efforts will be successful. In addition, the Company's products compete with the
products of many other companies that currently have extensive and well-funded
marketing and sales operations. There can be no assurance that the Company's
training, marketing and sales efforts will compete successfully against such
other companies. To the extent the Company enters arrangements with third
parties, any revenues received by the Company will be dependent on the efforts
of such third parties, and there can be no assurance that such efforts will be
successful.

COMPETITION AND TECHNOLOGICAL CHANGE

The diagnostic and biotechnology industries are subject to intense
competition and rapid and significant technological change. Competitors of the
Company in the United States and in foreign countries are numerous and include,
among others, diagnostic, health care, pharmaceutical, biotechnology and
chemical companies, academic institutions, government agencies and other public
and private research organizations. Many of these competitors have substantially
greater financial and technical resources and production and marketing
capabilities than the Company. There can be no assurance that these competitors
will not succeed in

<PAGE> 11

developing technologies and products that are more effective, easier to use or
less expensive than those that have been or are being developed by the Company
or that would render the Company's technology and products obsolete and
noncompetitive. The Company also competes with various companies in acquiring
technology from academic institutions, government agencies and research
organizations. In addition, many of the Company's competitors have significantly
greater experience than the Company in conducting clinical trials of new
diagnostic products and in obtaining FDA and other regulatory approvals of
products for use in health care. Accordingly, the Company's competitors may
succeed in obtaining regulatory approval for products more rapidly than the
Company.

INVESTMENT IN ONCORMED, APPLIGENE, AND CODON

The Company owns approximately 23% and 80% of the common stock of
its publicly-traded affiliates, Oncormed and Appligene, respectively, and 100%
of the outstanding capital stock securities of its privately held subsidiary,
Codon. The shares of common stock of Oncormed, Appligene, and Codon held by the
Company are not currently freely tradeable and no public market exists for the
common stock of Codon. Therefore, there can be no assurance that the Company
will be able to realize the economic benefit of its investment or predict the
timing of such realization. The value of the Company's investment in Oncormed
and Appligene represents a significant portion of the total assets of the
Company and such value fluctuates with the market price of those companies'
common stock. Therefore, any event that has a material and adverse effect on the
market price of the common stock of Oncormed and Appligene will have a material
and adverse effect on the value of the Company's investment in those companies.
The Company does not control the day-to-day operations and management of those
companies and, therefore, has a varying but limited direct control over their
operations and financial results.

As described above, Oncormed announced in July 1998 that it had
reached a definitive agreement to merge with Gene Logic which, if consummated,
will result in Oncor's shares of Oncormed not subject to outstanding options
being converted into shares of Gene Logic. However, there can be no assurance
that the merger between Oncormed and Gene Logic will, in fact, be consummated
and in the event such merger is not consummated, the shares of Oncormed owned by
Oncor that are not subject to outstanding options can be sold in the public
markets only pursuant to restrictions on the sale of unregistered stock by an
affiliate pursuant to Rule 144 of the Securities Act of 1933 such that the
complete liquidation of Oncor's position in Oncormed likely would take a year or
more.

<PAGE> 12

RESTRICTED USE OF THE COMPANY'S PRODUCTS

The sale, distribution and use of the Company's FDA approved breast
cancer product in the United States is restricted to prescription use in that
the users of the product must be trained and demonstrated proficient in the use
of the product and the results of the proficiency testing provided as part of
the Company's training program must be provided in the Company's Annual Reports
to the FDA. The Company's products sold in the United States for research
purposes, only, must be labeled accordingly. The FDA imposes distribution
requirements and procedures on companies selling products for research purposes
only, including the requirement that the seller receive specified certifications
from its customer as to the customer's intended use of the product. As a result
of these requirements, the Company's research products can only be sold in the
United States to a limited number of customers for limited use and can only be
sold for broader commercial use with FDA approval or clearance or pursuant to
recent Analyte Specific Reagent regulations for which no clinical claims can be
made. No assurance can be given that the Company will receive FDA approval or
clearance for its research products or that it will be able to sell its approved
products in larger quantities.

ATTRACTION AND RETENTION OF KEY PERSONNEL

The Company's ability to successfully develop marketable products
and to maintain a competitive position will depend in large part on its ability
to attract and retain highly qualified scientific and management personnel. The
Company is highly dependent upon the principal members of its management,
scientific staff, and Medical and Science Advisory Boards. Competition for such
personnel and advisors is intense, and the Company's ability to attract and
retain such personnel is adversely affected by the current financial condition
of the Company; therefore, there can be no assurance that the Company will be
able to continue to attract and retain such personnel.

UNCERTAINTY RELATED TO HEALTH CARE REFORM
MEASURES AND THIRD-PARTY REIMBURSEMENT

Political, economic and regulatory influences are likely to lead to
fundamental change in the health care industry in the United States. In the past
year, the U.S. FDA Modernization Act ("FDAMA") was approved, bringing many
changes to FDA regulations and codifying some current practices. In addition,
numerous proposals for comprehensive reform of the nation's health care system
have been introduced in Congress over the past year. In addition, certain states
are considering various health care reform proposals. The Company anticipates
that Congress and state legislatures will continue to review and assess
alternative health care delivery systems and payment methodologies, and that
public debate of these issues will likely continue in the future. Due to
uncertainties regarding the ultimate features of reform initiatives and their
enactment and implementation, the Company cannot predict which, if any, reforms
will be adopted, when they may be adopted, or what impact they may have on the
Company. The Company's ability to earn sufficient returns on its products may
also depend in part on the extent to which reimbursement for the costs of such
products will be available from government health administration authorities,
private health insurers and other organizations. Third-party payors

<PAGE> 13

are increasingly challenging the price and cost effectiveness of medical
products and services. Significant uncertainty exists as to the reimbursement
status of newly approved health care products, and there can be no assurance
that adequate reimbursement will be available or sufficient to allow the Company
to sell its products on a competitive basis.

PRODUCT LIABILITY

The testing, marketing and sale of health care products could expose
the Company to the risk of product liability claims. A product liability claim
could have a material and adverse effect on the business, results of operations
or financial condition of the Company. The Company currently maintains product
liability insurance coverage of $5.0 million per occurrence. There can be no
assurance, however, that the insurance policy will respond to any specific
claim, that this coverage will be adequate to protect the Company against future
product liability claims or that product liability insurance will be available
to the Company in the future on acceptable terms, if at all.

ENVIRONMENTAL RISKS

The manufacturing and research and development processes of the
Company involve the controlled use of hazardous materials. The Company is
subject to federal, state and local laws and regulations governing the use,
manufacture, storage, handling and disposal of such materials and certain waste
products. Although the Company believes that its activities currently comply
with the standards prescribed by such laws and regulations, the risk of
accidental contamination or injury from these materials cannot be eliminated. In
the event of such an accident, the Company could be held liable for any damages
that result and any such liability could exceed the resources of the Company. In
addition, there can be no assurance that the Company will not be required to
incur significant costs to comply with environmental laws and regulations in the
future.

POSSIBLE VOLATILITY OF STOCK PRICE

The market prices for securities of life sciences companies,
including the market prices of the Company's Common Stock, have been highly
volatile and the market has experienced significant price and volume
fluctuations that are unrelated to the operating performance of particular
companies. Announcements of technological innovations or new commercial
products by the Company or its competitors, developments concerning proprietary
rights, including patents and litigation matters, publicity regarding actual or
potential clinical trial results with respect to products under development by
the Company or others, decisions regarding regulatory approvals of the products
of the Company or others, regulatory developments in both the United States and
foreign countries, public concern as to the efficacy of new technologies,
general market conditions, as well as quarterly fluctuations in the Company's
revenues and financial results and other factors, may have a significant impact
on the market price of the common stock. In particular, the realization of any
of the risks described in these "Risk Factors" could have a dramatic and
adverse impact on such market price.

<PAGE> 14

LARGE NUMBER OF SHARES ELIGIBLE FOR FUTURE SALE; EFFECT ON ABILITY TO RAISE
CAPITAL

Sales of substantial amounts of Common Stock in the public market
following this Offering could adversely affect the prevailing market price of
the Company's Common Stock and may have a material and adverse effect on the
Company's ability to raise the capital necessary to fund its future operations.
As of July 31, 1998, without taking into account shares of Common Stock
issued upon exercise of stock options, warrants or other rights to acquire
Common Stock after July 31, 1998, the Company had outstanding 31,377,080
shares of Common Stock. The Shares and substantially all of the shares of
Common Stock already outstanding, will be freely tradeable in the public market
without restriction under the Securities Act, except that any shares held by
"affiliates" of the Company, as such term is defined in Rule 144(a) under the
Securities Act ("Affiliates"), may generally only be sold in compliance with
the applicable provisions of Rule 144 of the Securities Act. In general, under
Rule 144 an Affiliate is entitled to sell within any three-month period a
number of shares that does not exceed the greater of 1% of the then outstanding
shares of the Company's Common Stock (approximately 313,770 shares) or the
average weekly trading volume in the Company's Common Stock on the American
Stock Exchange during the four calendar weeks preceding the date on which
notice of such sale was filed under Rule 144. Sales under Rule 144 are also
subject to certain provisions relating to the manner and notice of sale and the
availability of current public information about the Company. Additional
shares of Common Stock, including shares issuable upon exercise of options,
warrants and other rights to acquire Common Stock, will also become eligible
for sale in the public market from time to time in the future. Furthermore,
certain holders of Common Stock have the right to cause the Company to register
their shares under the Securities Act in the future. The Company is required
to bear the expenses of all such required registrations (except underwriting
discounts and commissions). The Company is required to use its best efforts to
effect such registrations, subject to certain conditions and limitations.

NO DIVIDENDS

The Company has never paid any cash dividends on its Common Stock and
does not anticipate paying any cash dividends in the foreseeable future.

TERMS OF THE PREFERRED STOCK AND WARRANTS

Each share of Series A Preferred Stock is convertible into that number
of shares of Common Stock equal to 10,000 divided by the lesser of (i) 110% of
the Market Price on the date of issuance of the Preferred Shares (i.e., $4.54
for the Preferred Stock issued on January 8, 1998) and (ii) the Market Price on
the date such Preferred Shares are converted into Common Stock times a
percentage declining from 100% on the date of issuance of the Preferred Shares
to 90% for periods more than 180 days after the date of issuance. For purposes
of this calculation, the term "Market Price" means the average of the two lowest
closing bid prices for the Common Stock during the 22 consecutive trading days
immediately preceding the date of conversion. The holders of Series A Preferred
Stock have the following rights and preferences: (i) the right to convert their
shares of Preferred Stock into shares of the Company's Common Stock as described
in the preceding paragraph, (ii) the right to redeem their shares of Preferred
Stock in certain circumstances specified in the Articles Supplementary of the
Company, relating to such shares, which was filed with the State of Maryland on
January 6, 1998 and which is an exhibit to the Registration Statement of which
this Prospectus forms a part, and (iii) a liquidation preference pursuant to
which such holders are entitled to be repaid in the event of a liquidation,
dissolution or winding-up of the Company prior to any payments being made to the
holders of the Company's Common Stock. The holders of Series A Preferred Stock
have no voting rights.

Each Warrant is exercisable, upon payment of the Warrant Exercise
Price (as defined below), to purchase one share of Common Stock. The Warrant
Exercise Price is equal to 125% of the Market Price of the Common Stock on the
date of issuance of the related Preferred Shares, or $5.156 for the Warrants
issued on January 8, 1998. The Warrants are exercisable for a period of five
years after the date of their issuance. The holders of Warrants have the right
to utilize a cashless exercise feature pursuant to which the Warrant may be
exercised without the payment of the exercise price in cash but instead by
utilizing the Warrants themselves as payment of the exercise price. The holders
of Warrants have no voting rights.

But for the limitation described in Note 1 to the Selling Stockholders
table, the number of shares of Common Stock into which outstanding
shares of Series A Preferred Stock would be converted, as of August 19, 1998,
equals 14,814,814 and the number of shares of Common Stock into which the
Warrants would be exercisable as of such date equals 125,000. The conversion of
some or all of the Series A Preferred Stock, and the exercise of some or all of
the Warrants, will have the effect of increasing the number of shares of the
Company's Common Stock which will then be outstanding, thereby diluting the
percentage of the Company owned by the existing holders of such Common Stock
and, all other factors being equal, putting downward pressure on the market
price of such Common Stock.

- 10 -
<PAGE> 15
ISSUANCE OF THE SHARES; RESTRICTIONS ON THE USE OF PROCEEDS

The Shares are issuable upon the conversion or exercise of outstanding
Series A Preferred Stock and Warrants.

None of the proceeds from the sale of the Shares by the Selling
Stockholders issued upon conversion of the Series A Preferred Stock will be
received by the Company.

The Shares issuable upon the exercise of the Warrants outstanding as
of the date of this Prospectus will be acquired by the Selling Stockholders at
a purchase price per share of $5.156, subject to adjustment to prevent
dilution. The Company will receive aggregate gross proceeds of up to $644,500
upon the exercise of such Warrants. The number and exercise price of the
warrants issuable in connection with future issuances of Series A Preferred
Stock is dependent on the number of shares of Series A Preferred Stock issued
and the market price of the Common Stock at such time.

The Company is restricted in the use of the net proceeds, if any, from
the exercise of the Warrants. Specifically, certain of the funds raised by the
Company, including net proceeds from the exercise of the Warrants, must be
utilized to repay the Company's bank debt of $4.0 million in accordance with
the terms of the underlying line of credit and related guarantees.
Consequently, the Company will not receive any proceeds from the exercise of
the Warrants.

BUSINESS

RECENT DEVELOPMENTS

On April 9, 1998, the Company entered into a definitive agreement with
Vysis, Inc. and the University of California to settle a lawsuit which had been
filed by the University of California and Vysis against the Company. As part of
the agreement, the Company, Vysis and the Regents of the University of
California stipulated to a final judgment order which was approved and issued
by the U.S. District Court for the Northern District of California. Under the
terms of the definitive agreement, the Company obtained a world-wide
nonexclusive royalty-bearing license to U.S. Patent No. 5,447,841 and any
divisionals, continuations, continuations-in-part, reissues, extensions,
reexaminations, substitutions, renewals and foreign counterparts thereof
throughout the world for use in the fields of human oncology for both clinical
and research applications. The Company also obtained a nonexclusive
royalty-bearing license to certain direct labeling technology rights owned by
Vysis in U.S. Patent 5,491,224 and any divisionals, continuations,
continuations-in-art, reissues, extensions, reexaminations, substitutions,
renewals and foreign counterparts thereof throughout the world. In return, the
Company has agreed to convey to Vysis its fluorescence in situ hybridization
(FISH) genetic probe business, retaining full rights to the field of human
oncology for research and clinical applications, including the Company's
recently FDA approved INFORM HER-2/neu breast cancer test. Sales of the
conveyed FISH products represented less than $3.0 million of the Company's 1997
gross revenues. The Company also made initial cash payments to Vysis of $0.5
million, and an additional payment of $1.5 million will be due on April 10,
2000 in order to extend the licenses beyond that date.

On June 30, 1998, the Company completed the sale of its Research
Products Division to Intergen Company, L.P. for an aggregate consideration of
$3.2 million, of which $200,000 is payable in scheduled payments over the next
two years. In connection with this transaction, the Company (i) assigned its
apoptosis and telemerase license agreements and (ii) licensed its sunrise and
methylation technologies to Intergen for exclusive use in the research products
field, while retaining exclusive rights to such licenses and technologies for
the field of therapeutic and diagnostic products. In addition, Oncor and
Intergen agreed to co-exclusive licenses to such licenses and technologies for a
field that includes clinical research, and development activities and sales of
products for clinical research and development activities. Sales to
non-affiliated companies generated by the Research Products Division in 1997
were approximately $3.0 million. Of the approximately $3.0 million in cash that
Oncor received upon the consummation of this transaction, approximately $2.5
million was used to increase the Company's net working capital and the
remaining $400,000 was used to repay certain outstanding bank debt. The Company
recorded a gain of approximately $1.8 million upon the closing of this
transaction.

On August 14, 1998, Oncor signed a non-binding Letter of Intent for the
sale of the assets of Codon, its wholly-owned subsidiary, to Codon Acquisition
Holdings, LLC, a company organized by Perseus Capital, LC, a Washington,
D.C.-based banking venture. Codon is a developer of gene recognition and repair
technology for the correction, alteration and therapeutic regulation of genes
for the treatment of disease. The transaction is expected to close during
September 1998. However, there can be no assurance that this transaction will,
in fact, be consummated.

LEGAL PROCEEDINGS

From time to time, the Company may be involved in litigation relating
to claims arising out of its operations in the normal course of business, in
addition to the pending and threatened legal proceedings discussed in "Risk
Factors" above, or receive notification from third parties threatening to
commence such litigation. See "Risk Factors -- Patents and Proprietary
Rights." The Company is not currently a party to any such legal proceedings
relating to claims arising out of its operations in the normal course of
business, the adverse outcome of which, individually or in the aggregate, would
have a material and adverse effect on the Company's business, financial
condition or results of operations.

- 11 -
<PAGE> 16
SELLING STOCKHOLDERS

The following table sets forth the number of shares of Common Stock
beneficially owned by each of the Selling Stockholders as of June 30, 1998.
None of the Selling Stockholders has had a material relationship with the
Company within the past three years other than as a result of the ownership of
the Shares or other securities of the Company. The Shares offered by this
Prospectus may be offered from time to time by the Selling Stockholders. See
"Plan of Distribution."

The Shares being offered by the Selling Stockholders may be acquired,
from time to time, (i) upon conversion of shares of Series A Preferred Stock
issued and issuable to the Selling Stockholders, (ii) upon the exercise of
Warrants issued and issuable to the Selling Stockholders in connection with the
issuance of the shares of Series A Preferred Stock and (iii) pursuant to
certain anti-dilution provisions included in the Series A Preferred Stock and
the Warrants.

<TABLE>
<CAPTION>
BENEFICIAL OWNERSHIP
NUMBER OF SHARES NUMBER OF AFTER OFFERING(4)
BENEFICIALLY OWNED SHARES ----------------------
PRIOR TO REGISTERED FOR NUMBER
NAME OF SELLING STOCKHOLDER OFFERING(1)(2) SALE HEREBY(3) OF SHARES PERCENT
--------------------------- -------------------- -------------- --------- -------
<S> <C> <C> <C> <C>
Halifax Fund, L.P.(11). . . . . . . . . 3,055,398(5) 2,793,982 261,416 *
Heracles Fund(12) . . . . . . . . . . . 941,378(6) 838,195 103,183 *
Themis Partners L.P.(13). . . . . . . . 871,128(7) 838,195 32,933 *
Leonardo, L.P.(14). . . . . . . . . . . 622,745(8) 558,796 63,949 *
Ramius Fund, Ltd.(15) . . . . . . . . . 342,778(9) 335,278 7,500 *
Raphael, L.P.(16) . . . . . . . . . . . 242,278(10) 223,519 18,759 *
--------- --------- --------- ---------
TOTAL . . . . . . . . . . . . 6,075,705 5,587,965 487,740 1.6%
========= ========= ========= =========
</TABLE>

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

* Less than one percent.

(1) Beneficial ownership is determined in accordance with the rules and
regulations promulgated under the Securities Act and generally
includes voting or investment power with respect to securities.
Pursuant to the terms of the Series A Preferred Stock and the
Warrants, no Selling Stockholder can convert any portion of such
Selling Stockholder's Series A Preferred Stock or exercise any portion
of such Selling Stockholder's Warrants if such conversion or exercise
would increase such Selling Stockholder's beneficial ownership of the
Common Stock (other than shares so owned through ownership of the
Series A Preferred Stock or Warrants) to in excess of 4.99%.

(2) Includes shares of Common Stock of the Company held by certain of the
Selling Stockholders and shares of Common Stock of the Company
issuable within 60 days of June 30, 1998 upon (i) conversion of the
Series A Preferred Stock calculated using an assumed conversion price
of $0.5625 (calculated as of June 30, 1998), based upon certain
conversion provisions of the Series A Preferred Stock (which price
could fluctuate from time to time based on changes in the market price
of the Common Stock), (ii) exercise of the Warrants, (iii) exercise of
certain warrants issued in 1996 which have been adjusted as of January
15,

- 12 -
<PAGE> 17
1998 pursuant to certain anti-dilution adjustment provisions (the
"1996 Warrants"), and (iv) conversion of certain convertible
debentures issued in 1996 (the "1996 Debentures"), as more
specifically disclosed in footnotes 5 through 10 below. This number
does not include shares of Common Stock issuable upon conversion of
Series A Preferred Stock and exercise of Warrants which may be sold to
the Selling Stockholders after January 15, 1998, pursuant to the terms
of the Securities Purchase Agreement, dated January 8, 1998, by and
among the Company and the buyers named therein.

(3) Represents each Selling Stockholder's pro rata portion (based on the
number of shares of Series A Preferred Stock purchased by such Selling
Stockholder) of the specified number of shares of Common Stock which
the Company has agreed initially to register for resale by the Selling
Stockholders.

(4) The number of shares of Common Stock and the percentage of shares of
Common Stock beneficially owned by each Selling Stockholder after the
Offering are based on the assumption that each Selling Stockholder
will sell all of the Series A Shares and Warrant Shares registered for
sale hereby. See "Plan of Distribution."

(5) Consists of (i) 2,793,982 shares of Common Stock issuable upon
conversion of the Series A Preferred Stock, (ii) 62,500 shares of
Common Stock issuable upon exercise of the Warrant, and (iii) an
aggregate of 198,916 shares of Common Stock issuable upon exercise of
the 1996 Warrants.

(6) Includes (i) 838,195 shares of Common Stock issuable upon conversion
of the Series A Preferred Stock, (ii) 18,750 shares of Common Stock
issuable upon exercise of the Warrant, and (iii) an aggregate of
84,433 shares of Common Stock issuable upon exercise of the 1996
Warrants, each as of June 30, 1998.

(7) Includes (i) 838,195 shares of Common Stock issuable upon conversion
of the Series A Preferred Stock, (ii) 18,750 shares of Common Stock
issuable upon exercise of the Warrant, and (iii) 14,183 shares of
Common Stock issuable upon exercise of the 1996 Warrant, each as of
June 30, 1998.

(8) Consists of (i) 558,796 shares of Common Stock issuable upon
conversion of the Series A Preferred Stock, (ii) 12,500 shares of
Common Stock issuable upon exercise of the Warrant, and (iii) 51,449
shares of Common Stock issuable upon exercise of the 1996 Warrant, each
as of June 30, 1998.

(9) Consists of (i) 335,278 shares of Common Stock issuable upon conversion
of the Series A Preferred Stock, and (ii) 7,500 shares of Common Stock
issuable upon exercise of the Warrant, each as of June 30, 1998.

(10) Consists of (i) 223,519 shares of Common Stock issuable upon conversion
of the Series A Preferred Stock, (ii) 5,000 shares of Common Stock
issuable upon exercise of the Warrant, and (iii) an aggregate of
13,759 shares of Common Stock issuable upon exercise of the 1996
Warrants, each as of June 30, 1998.

(11) The Palladin Group, L.P. is the investment manager of Halifax Fund,
L.P. and consequently has voting control and investment discretion
over securities held by the Halifax Fund, L.P. The Palladin Group, L.P.
is indirectly controlled by Mr. Jeffrey E. Devers. The Palladin Group
L.P. and Mr. Devers disclaim beneficial ownership of the Shares held by
Halifax Fund, L.P.

(12) Promethean Investment Group L.L.C. is the general partner of
Themis Partners L.P. and the investment advisor for Heracles Fund
(collectively, the "Promethean Entities") and consequently has voting
control and investment discretion over securities held by the
Promethean Entities. Promethean Investment Group L.L.C. is indirectly
controlled by Mr. James F. O'Brien, Jr. The ownership for each of the
Promethean Entities does not include the ownership information for the
other Promethean Entities. Promethean Investment Group L.L.C. and each
of the Promethean Entities disclaims beneficial ownership of the Shares
held by the other Promethean Entities. Mr. O'Brien disclaims beneficial
ownership of the shares beneficially owned by Promethean Investment
Group L.L.C. and the Promethean Entities.

(13) Promethean Investment Group L.L.C. is the general partner of
Themis Partners L.P. and the investment advisor for Heracles Fund
(collectively, the "Promethean Entities") and consequently has voting
control and investment discretion over securities held by the
Promethean Entities. Promethean Investment Group L.L.C. is indirectly
controlled by Mr. James F. O'Brien, Jr. The ownership for each of the
Promethean Entities does not include the ownership information for the
other Promethean Entities. Promethean Investment Group L.L.C. and each
of the Promethean Entities disclaims beneficial ownership of the Shares
held by the other Promethean Entities. Mr. O'Brien disclaims beneficial
ownership of the shares beneficially owned by Promethean Investment
Group L.L.C. and the Promethean Entities.

(14) Angelo, Gordon & Co., L.P. is a general partner of Leonardo, L.P., a
general partner of Raphael, L.P. and the Investment Managing Member of
AG Ramius Partners, L.L.C., the Investment Advisor of Ramius Fund,
Ltd., (collectively, the "Angelo Gordon Entities") and consequently has
voting control and investment discretion over securities held by Angelo
Gordon Entities. The ownership for each of the Angelo Gordon Entities
does not include the ownership information for the other Angelo Gordon
Entities. Mr. John M. Angelo, the Chief Executive Officer of Angelo,
Gordon & Co., L.P., and Mr. Michael R. Gordon, the Chief Operating
Officer of Angelo, Gordon & Co., L.P., are the sole general partners
of AG Partners, L.P., the sole general partner of Angelo, Gordon &
Co., L.P. As such, Mr. Angelo and Mr. Gordon may be considered
beneficial owners of any shares deemed to be beneficially owned by
Angelo, Gordon & Co., L.P.

(15) Angelo, Gordon & Co., L.P. is a general partner of Leonardo, L.P., a
general partner of Raphael, L.P. and the Investment Managing Member of
AG Ramius Partners, L.L.C., the Investment Advisor of Ramius Fund,
Ltd., (collectively, the "Angelo Gordon Entities") and consequently has
voting control and investment discretion over securities held by Angelo
Gordon Entities. The ownership for each of the Angelo Gordon Entities
does not include the ownership information for the other Angelo Gordon
Entities. Mr. John M. Angelo, the Chief Executive Officer of Angelo,
Gordon & Co., L.P., and Mr. Michael R. Gordon, the Chief Operating
Officer of Angelo, Gordon & Co., L.P., are the sole general partners
of AG Partners, L.P., the sole general partner of Angelo, Gordon &
Co., L.P. As such, Mr. Angelo and Mr. Gordon may be considered
beneficial owners of any shares deemed to be beneficially owned by
Angelo, Gordon & Co., L.P.

(16) Angelo, Gordon & Co., L.P. is a general partner of Leonardo, L.P., a
general partner of Raphael, L.P. and the Investment Managing Member of
AG Ramius Partners, L.L.C., the Investment Advisor of Ramius Fund,
Ltd., (collectively, the "Angelo Gordon Entities") and consequently has
voting control and investment discretion over securities held by Angelo
Gordon Entities. The ownership for each of the Angelo Gordon Entities
does not include the ownership information for the other Angelo Gordon
Entities. Mr. John M. Angelo, the Chief Executive Officer of Angelo,
Gordon & Co., L.P., and Mr. Michael R. Gordon, the Chief Operating
Officer of Angelo, Gordon & Co., L.P., are the sole general partners
of AG Partners, L.P., the sole general partner of Angelo, Gordon &
Co., L.P. As such, Mr. Angelo and Mr. Gordon may be considered
beneficial owners of any shares deemed to be beneficially owned by
Angelo, Gordon & Co., L.P.

The Shares are being registered as a result of the contractual
arrangement with the Selling Stockholders. The Company has agreed to bear
certain expenses (other than underwriting discounts and selling commissions and
fees and disbursements of counsel and other advisors to the Selling
Stockholders) in connection with the registration of the Shares.

The Company has agreed to prepare and file such amendments and
supplements to the Registration Statement as may be necessary to keep this
Registration Statement effective until the earlier of the date on which the
Selling Stockholders shall have sold all of the securities registered hereby or
the date on which the Shares are saleable pursuant to Rule 144(k) promulgated
under the Securities Act.

- 13 -

<PAGE> 18
PLAN OF DISTRIBUTION

The sale of the Shares offered hereby may be effected by the Selling
Stockholders from time to time in transactions on the American Stock Exchange,
in negotiated transactions, or a combination of such methods of sale, at fixed
prices which may be changed, at market prices prevailing at the time of sale,
at prices related to prevailing market prices or at negotiated prices. The
Selling Stockholders may effect such transactions by selling the Shares to or
through broker-dealers, and such broker-dealers may receive compensation in the
form of discounts, concessions or commissions from the Selling Stockholders
and/or the purchasers of the Shares for whom such broker-dealers may act as
agents or to whom they sell as principals, or both (which compensation as to a
particular broker-dealer might be in excess of customary commissions). In
order to comply with the securities laws of certain states, if applicable, the
Shares will be sold in such jurisdictions only through registered or licensed
brokers or dealers. The Selling Stockholders may transfer their Shares under
certain circumstances to other persons who may, in turn, resell Shares in the
manner described above. In addition, the Selling Stockholders may pledge or
make gifts of their Shares and such Shares may also be sold by the pledgees or
transferees.

In the event that a Selling Stockholder transfers his shares, pledges
his shares or makes a gift of his shares, the Company will amend this
Registration Statement or file a Prospectus Supplement, as appropriate,
identifying the transferee(s) as Selling Stockholder(s).

From time to time, one or more Selling Stockholders may pledge,
hypothecate or grant a security interest in some or all of the Shares owned by
them, and the pledgees, secured parties or persons to whom such securities have
been hypothecated shall, upon foreclosure in the event of default, be deemed to
be Selling Stockholders hereunder. In addition, a Selling Stockholder may,
from time to time, sell short the Common Stock of the Company, and in such
instances, this Prospectus may be delivered in connection with such short sales
and the Shares offered hereby may be used to cover such short sales.

At the time a particular offer of Shares is made, to the extent
required, a Prospectus Supplement will be distributed which will set forth the
number of Shares being offered and the terms of the offering including the name
or names of any underwriters, dealers or agents, the purchase price paid by any
underwriter for the Shares purchased from Selling Stockholders, any discounts,
commissions and other items constituting compensation from the Selling
Stockholders and any discounts, commissions or concessions allowed or reallowed
or paid to dealers.

In order to comply with the securities laws of certain states, if
applicable, the Shares will be sold in such jurisdictions only through
registered or licensed brokers or dealers. In addition, in certain states the
Shares may not be sold unless they have been registered or qualified for sale
in the applicable state or an exemption from the registration or qualification
requirement is available and is complied with by the Company and the Selling
Stockholders.

The Selling Stockholders may also transfer their Shares pursuant to
Rule 144, whether or not the Registration Statement, of which this Prospectus
forms a part, is effective at the time of any such transfer.

The Selling Stockholders and any broker-dealers, agents or
underwriters that participate with the Selling Stockholders in the distribution
of the Shares may be deemed to be "underwriters" within the meaning of Section
2(11) of the Securities Act, and any commissions received by them and any
profit on the resale of the Selling Stockholder Shares purchased by them may be
deemed to be underwriting commissions or discounts under the Securities Act.
The Company has agreed to indemnify the Selling Stockholders and their
affiliates against certain liabilities, including liabilities under the
Securities Act. The Selling Stockholders have agreed to indemnify the Company
and its affiliates against certain liabilities, including liabilities under the
Securities Act.

Under applicable rules and regulations under the Exchange Act, any
person engaged in the distribution of the Shares may not simultaneously engage
in market making activities with respect to the Common Stock of the Company for
a period of two business days prior to the commencement of such distribution.
In addition and without limiting the foregoing, each Selling Stockholder will
be subject to applicable provisions of the Exchange Act and the rules and
regulations thereunder, including, without limitation, Regulation M, which
provisions may limit the timing of purchases and sales of shares of the
Company's Common Stock by the Selling Stockholders.

- 14 -
<PAGE> 19
The Company has agreed to bear certain expenses (other than
underwriting discounts and selling commissions and fees and disbursements of
counsel and other advisors to the Selling Stockholders) in connection with the
registration of the Shares.

LEGAL MATTERS

The validity of the Shares offered hereby will be passed upon for the
Company by Brobeck, Phleger & Harrison LLP, New York, New York.

EXPERTS

The financial statements and schedules of the Company incorporated by
reference in this Prospectus and elsewhere in the Registration Statement have
been audited by Arthur Andersen LLP, independent public accountants, as
indicated in their reports with respect thereto, and are included herein in
reliance upon the authority of said firm as experts in giving said reports.

- 15 -
<PAGE> 20

5,587,965

ONCOR, INC.

COMMON STOCK

PROSPECTUS

AUGUST 20, 1998

<PAGE> 21
PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION

The following table sets forth an estimate of the expenses to be
incurred by the Company in connection with the issuance and distribution of the
securities being registered:
<TABLE>
<CAPTION>
Amount to
Be Paid
-----------
<S> <C>
Registration Fee - SEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 670
AMEX Listing Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17,500
Legal Fees and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20,000
Accounting Fees and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,500
Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,330
-------
Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $50,000
=======
</TABLE>

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS

Article 11 of the Registrant's Articles of Incorporation, as amended,
and Section 5-01 of the Registrant's By-Laws, as amended, provide that the
Registrant shall, to the full extent permitted by law, indemnify all directors,
officers, employees or agents of the Registrant. Section 2-418 of the Maryland
General Corporation Law permits indemnification of directors, officers,
employees, and agents of a corporation under certain conditions and subject to
certain limitations. The Section provides generally that such persons may be
indemnified unless they engage in a material act or omission in bad faith or
that is the result of active and deliberate dishonesty, they actually receive
an improper personal benefit in money, property or services, or, in the case of
a criminal proceeding, they have reasonable cause to believe that the act or
omission is unlawful. Provision is made for reimbursement of reasonable
expenses so long as it is finally determined that the standards of conduct have
been met. The Selling Stockholders have agreed to indemnify officers,
directors and controlling persons of the Registrant against certain
liabilities, including liabilities under the Securities Act under certain
circumstances.

The Company and its directors and officers have liability insurance.

ITEM 16. EXHIBITS

The following is a list of Exhibits filed as part of the Registration
Statement:

3.1 The Articles of Incorporation, as amended, of the Registrant,
incorporated herein by reference to Exhibit 3.1 to the Registrant's
Annual Report on Form 10-K for the fiscal year ended December 31,
1994.

3.2 The By-Laws of the Registrant, incorporated herein by reference to
Exhibit 3.2 to the Registrant's Annual Report on Form 10-K for the
fiscal year ended December 31, 1990.

4.1 Specimen certificate for shares of the Registrant's Common Stock,
incorporated herein by reference to Exhibit 4.1 to Registration
Statement No. 33-44520.

4.2 Specimen certificate for shares of the Registrant's Series A
Convertible Preferred Stock.*

4.3 Articles Supplementary of the Registrant defining rights of holders of
Series A Convertible Preferred Stock of the Registrant.*

4.4 Form of Common Stock Purchase Warrant.*

5.1 Opinion of Brobeck, Phleger & Harrison LLP.*

II-1
<PAGE> 22
10.1 Securities Purchase Agreement, dated as of January 8, 1998, between
the Registrant and the persons listed on the Schedule of Buyers
attached thereto.*

10.2 Registration Rights Agreement, dated as of January 8, 1998, between
the Registrant and the persons listed on the Schedule of Buyers
attached thereto.*

23.1 Consent of Arthur Andersen LLP, independent public accountants.**

23.2 Consent of Brobeck, Phleger & Harrison LLP (included in the opinion
filed as Exhibit 5.1).

24. Powers of Attorney (included with signature page).

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

*Previously filed.
**Filed herewith.

II-2
<PAGE> 23
ITEM 17. UNDERTAKINGS

Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the foregoing provisions, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act, and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than payment by the Registrant
of expenses incurred or paid by a director, officer or controlling person of
the Registrant in the successful defense of any action, suit or proceeding) is
asserted by such director, officer or controlling person in connection with the
securities being registered, the Registrant will, unless in the opinion of its
counsel the matter has been settled by controlling precedent, submit to a court
of appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Act and will be governed by the final
adjudication of such issue.

The undersigned Registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement;

(i) To include any prospectus required by Section 10(a)(3)
of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events
arising after the effective date of the registration statement (or the
most recent post-effective amendment thereof) which, individually or
in the aggregate, represent a fundamental change in the information
set forth in the registration statement. Notwithstanding the
foregoing, any increase or decrease in volume of securities offered
(if the total dollar value of securities offered would not exceed that
which was registered) and any deviation from the low or high end of
the estimated maximum offering range may be reflected in the form of
prospectus filed with the Commission pursuant to Rule 424(b) if, in
the aggregate, the changes in volume and price represent no more than
a 20 percent change in the maximum aggregate offering price set forth
in the "Calculation of Registration Fee" table in the effective
registration statement;

(iii) To include any material information with respect to the
plan of distribution not previously disclosed in the registration
statement or any material change to such information in the
registration statement;

provided, however, that the undertakings set forth in paragraphs (i) and (ii)
above do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in periodic reports
filed by the registrant pursuant to Section 13 or Section 15(d) of the
Securities Exchange Act of 1934 (the "Exchange Act") that are incorporated by
reference in this registration statement.

(2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to
be a new registration statement relating to the securities offered therein, and
the offering of such securities at that time shall be deemed to be the initial
bona fide offering thereof.

(3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act that is incorporated by reference in the registration statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

II-3
<PAGE> 24
SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as
amended, the Registrant certifies that it has reasonable grounds to believe
that it meets all of the requirements for filing on Form S-3 and has duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Gaithersburg, State of
Maryland, on August 20, 1998.

ONCOR, INC.

By:/s/ John L. Coker
------------------------------------------
John L. Coker
Vice President -- Finance and Administration,
and Chief Financial Officer

Pursuant to the requirements of the Securities Act of 1933, as
amended, this Registration Statement has been signed by the following persons
in the capacities indicated on August 20, 1998.

<TABLE>
<CAPTION>
Signature Title
--------- -----

<S> <C>

* Chairman of the Board of Directors
- ----------------------------------
Jose J. Coronas

* President, Chief Operating Officer and Director (principal executive officer)
- ----------------------------------
Cecil Kost

/s/ John L. Coker Vice President, Secretary and Treasurer
- ---------------------------------- (principal financial and accounting officer)
John L. Coker

* Director
- ----------------------------------
Derace L. Schaffer, M.D.

* Director
- ----------------------------------
William H. Taylor II

* Director
- ----------------------------------
Timothy J. Triche, M.D., Ph.D.

* Director
- ----------------------------------
Stephen Turner

</TABLE>
* By: /s/ John L. Coker
----------------------
John L. Coker
Attorney-in-Fact

<PAGE> 25
EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT
NO. DESCRIPTION PAGE
- ------- ----------- ----
<S> <C>
3.1 The Articles of Incorporation, as amended,of the Registrant, incorporated herein by
reference to Exhibit 3.1 to the Registrant's Annual Report on Form 10-K for the
fiscal year ended December 31, 1994 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.2 The By-Laws of the Registrant, incorporated herein by reference to
Exhibit 3.2 to the Registrant's Annual Report on Form 10-K for the
fiscal year ended December 31, 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1 Specimen certificate for shares of the Registrant's Common Stock, incorporated herein
by reference to Exhibit 4.1 to Registration Statement No. 33-44520 . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2 Specimen certificate for shares of the Registrant's Series A Convertible Preferred Stock* . . . . . . . . . . . . . . . .

4.3 Articles Supplementary of the Registrant defining rights of holders of Series A
Convertible Preferred Stock of the Registrant* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4 Form of Common Stock Purchase Warrant* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.1 Opinion of Brobeck, Phleger & Harrison LLP* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10.1 Form of Securities Purchase Agreement, dated as of January 8, 1998, between the Registrant and the persons listed on the
Schedule of Buyers attached thereto* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10.2 Form of Registration Rights Agreement, dated as of January 8, 1998, between the Registrant and the persons listed on the
Schedule of Buyers attached thereto* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23.1 Consent of Arthur Andersen LLP, independent public accountants** . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23.2 Consent of Brobeck, Phleger & Harrison LLP (included in the opinion filed as Exhibit 5.1) . . . . . . . . . . . . . . . .

24. Powers of Attorney (included with signature page) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
</TABLE>

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

*Previously filed.
**Filed herewith.

<PAGE> 1
EXHIBIT 23.1

CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement of our reports dated February 20, 1998
(except with respect to the financial condition of the Company described in
Note 1, and to the Vysis and Key Technology matters described in Note 8, as to
which the date is April 30, 1998) included in Oncor, Inc.'s Amendment No. 1 to
Form 10-K for the year ended December 31, 1997 and to all references to our
Firm included in this registration statement.

/s/ Arthur Andersen LLP
-------------------------------
Arthur Andersen LLP

Washington, D.C.
August 19, 1998