<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS FINANCIAL INFORMATION EXTRACTED FROM THE FINANCIAL
STATEMENTS FOR REPLIGEN CORPORATION AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> MAR-31-2000
<PERIOD-END> SEP-30-2000
<CASH> 27,372
<SECURITIES> 5,869
<RECEIVABLES> 575
<ALLOWANCES> (25)
<INVENTORY> 550
<CURRENT-ASSETS> 34,215
<PP&E> 1,825
<DEPRECIATION> (1,323)
<TOTAL-ASSETS> 34,773
<CURRENT-LIABILITIES> 968
<BONDS> 0
0
0
<COMMON> 266
<OTHER-SE> 33,540
<TOTAL-LIABILITY-AND-EQUITY> 34,773
<SALES> 880
<TOTAL-REVENUES> 2,190
<CGS> 559
<TOTAL-COSTS> 4,373
<OTHER-EXPENSES> 0
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 0
<INCOME-PRETAX> 0
<INCOME-TAX> 0
<INCOME-CONTINUING> 0
<DISCONTINUED> 0
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (2,183)
<EPS-BASIC> (0.08)
<EPS-DILUTED> (0.08)
</TABLE>