PRELIMINARY OPPOSITION PROXY MATERIAL

                      ASSET VALUE FUND LIMITED PARTNERSHIP
                          376 MAIN STREET, P.O. BOX 74
                              BEDMINSTER, NJ 07921
                                 (908) 234-1881

   
                                                                    June__, 1998
    

Dear Fellow Cortech Stockholder:

   
     We and two other  investors  ("Asset Value") own  approximately  15% of the
outstanding shares ("Cortech Shares") of Cortech, Inc. ("Cortech"),  which makes
us by far Cortech's  largest  stockholders.  We believe that the incumbent Board
has  exercised  poor judgment in governing  Cortech.  That is why we are seeking
your vote at the upcoming  Annual Meeting to elect all of our nominees who would
then constitute a majority of the Board.1

     At the end of fiscal  1997,  Cortech  had net assets of only $15.4  million
after  losing  over $70  million  since  1993 in a  failed  attempt  to  exploit
Cortech's  technology.  The Board then proceeded to expend $673,000 of Cortech's
limited  resources  promoting a merger with  BioStar,  Inc.  (the  "Merger"),  a
company  with a $5.6  million  negative net worth even though Asset Value warned
the  Board  from  the  start  that  the  Merger  was  not  in the  interests  of
stockholders2 who, Asset Value said, would never approve such a transaction. The
Merger was canceled on May 7,1998.  Within two weeks,  Kenneth Lynn,  the former
CEO, left Cortech,  taking with him, what we would call, a "departure  bonus" of
almost $500,000, another 3.5% of Cortech's remaining cash of $14.3 million.

                    We ask you. What will this Board do next?

Don't  take a chance.
Vote for a change.
Vote for Asset Value's nominees!

                                  MORE RED INK!

     After the  termination  of the  Merger,  Cortech's  Form 10-Q for the first
quarter of 1998 revealed that Cortech's  losses not only continued but increased
compared to last year. In a quarter with No research and development  activities
and No revenues, Cortech still had approximately 15
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        1 Asset Value is also asking stockholders to approve an amendment to the
By-laws which would increase the number of directors from five to seven creating
a total of four vacancies. If these four vacancies are filled with Asset Value's
nominees control of Cortech would transfer to Asset Value.

        2 Asset Value has not retained an independent  financial adviser and its
conclusions  are  solely  based  on the  opinion  of its  manager,  Asset  Value
Management,  Inc. which was reached after reviewing  management's proxy material
for the Merger, including the opinion of management's financial adviser.






full-time3 employees and general and administrative  expenses of $1,522,000,  of
which,  according to Cortech,  merger expense only  accounted for  approximately
$673,000

                         TIME AND MONEY ARE RUNNING OUT!

     On May 18,  1998,  CEO Kenneth  Lynn left Cortech . We believe that Mr Lynn
was made a scapegoat for what we think is Cortech's prior mismanagement.  But in
our  opinion,  Mr.  Lynn was a symptom  of what is wrong  with  Cortech  not the
source,  at least,  in our view,  not the only  source.  In the past five  years
(including the first quarter of 1998), Cortech has lost over $70 million, and as
of March 31, 1998 had cash of only  $14.3million.  We ask, does Lynn's departure
absolve the Board of their  responsibility for these losses? We think the answer
is a resounding No!

                   PICTURE OF HOUR GLASS WITH CONTENTS READING


                                                         CASH REMAINING AT
                                                          MARCH 31, 1998
                                                           $14.3 million





                                                          LOSSES INCEPTION 
                                                             TO DATE
                                                           $86 million!!!






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        3 Cortech  does not  disclose  whether  there are  additional  part-time
employees and consultants still hanging on.






               The question we believe you should ask yourself, is

                 ARE YOU BETTER OFF NOW THAN YOU WERE FIVE YEARS
                                      AGO?

     In what we think is the  biggest  bull  market in  history,  Cortech  Stock
prices  have  declined  from $18.25 per share in 1993 to $.50 per share in 1998,
making Cortech, by any comparison,  in our view, one of the poorest stock market
performers during this period. --AND THAT'S NO BULL!


                COMPARISON OF CORTECH'S STOCK PERFORMANCE (NASDAQ
           SYMBOL-CRTQ) TO THE DOW JONES INDUSTRIAL AVERAGE (DJII) AND
                THE STANDARD AND POOR'S 500 COMPOSITE INDEX (S&P)




 [GRAPH THE ABOVE]




                                    
                    DJII               S&P            Cortech
                   ------             -----          ---------
                                            
1993               3820.77            469.90         $18.25

1994               3867.41            460.68          14.25

1995               5181.43            616.71           3.65625

1996               6544.09            748.03           3.8125

1997               7908.25            970.43           2.03125

1998               9037.71           1113.86            .50



                              NOT A PRETTY PICTURE!






                               STOP THE RED INK!

     Asset Value  considers a shutdown of Cortech an  alternative  which must be
considered,  particularly in view of the continued  losses reported in the first
quarter of 1998.  Such a course  however,  has  risks,  including  the  possible
further  diminishment  of Cortech's  technology  and the  possible  cessation of
Cortech as a going concern.  The matter would be further  evaluated with current
employees once Asset Value gained control,  therefore, no assurance can be given
that Cortech would be shut down.

     Asset Value can only give stockholders the assurance that its nominees will
try to further reduce Cortech's expenses and will move as quickly as possible to
secure a merger partner. Expenses that will be particularly scrutinized for cuts
are any part-time employees or consultants and employees engaged in any activity
other than  caretaking.  The new Board would seek to reduce,  if  possible,  any
professional  fees  unrelated  to seeking a  strategic  partner.  Asset  Value's
nominees have pledged to take no fees for serving as directors.

                          THE SHAPE OF THINGS TO COME 4

     So, what will Asset Value do if it obtains control of the Cortech Board? We
believe that once the Cortech Board determined to change control of Cortech,  it
should have sought competitive transactions more aggressively, by advertising in
the financial media, by engaging an investment banker from the outset to solicit
merger  partners and by publicly  stating that the Board was  conducting an open
bidding process for control of Cortech.  If elected Asset Value's  nominees will
take these  steps.  Asset Value has no specific  merger  partner in mind and has
considered possible alternatives for the future of Cortech only in a preliminary
way. In the course of its own business,  however, Asset Value constantly reviews
investment  opportunities and in connection with this process has seen companies
which might be attractive  strategic  partners for Cortech  although  additional
analysis would be required to determine whether any of these companies are a fit
with Cortech.

     The  principal  standards  for seeking a candidate  would be balance  sheet
quality and positive earnings.  Asset Value also believes that a private company
which seeks a public market or a public company which needs Cortech's  assets to
qualify  for  NASDAQ,  would  consider  these  attributes  as  well  as  cash in
calculating  Cortech's value. Asset Value is not sure,  however,  that there are
potential  acquisitions  or mergers that would be  attractive  for Cortech.  One
thing is certain  however,  Asset Value will not seek to merge  Cortech with any
affiliate or entity in which Asset Value is an investor.  Asset Value intends to
benefit from its Cortech  investment only to the same extent other  stockholders
benefit.
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        4 H.G. Wells






                 "WHO CARES WHAT OWNERS THINK? Who owns American
 companies? The management, of course. Shareholders are tolerated, but managers
                                    rule.5"

     Seven months after Asset Value first asked for representation on the Board;
long after the Board was sued for misfeasance;  after Cortech had spent $673,000
on the failed Merger; after Cortech had lost another  approximately $3.4 million
from operations (from September 30, 1997 through March 31, 1998), finally on May
11, 1998 the Cortech  Board  expressed an interest in meeting with Asset Value's
manager,  Paul Koether.  By this time, Asset Value had already spent significant
amounts of its own funds opposing the Merger and attempting to secure control of
the Board because it believed that a change in course for Cortech was absolutely
essential  and because it believed  that a Board  controlled  by the  incumbents
would not  embrace  the  necessary  changes.  Still  Asset  Value was willing to
present  the issues in  dispute to  stockholders  in one proxy  statement  filed
jointly by the Board and by Asset Value to avoid the cost of this proxy contest.
Asset  Value even  offered  to pay its share of the costs.  The Board has yet to
respond to this  proposal.  Asset  Value's  position  and Asset  Value's view of
management's  position is more fully set forth in the enclosed  Proxy  Statement
which we urge you to read carefully.

     Now it is time  for the  Annual  Meeting;  time  for  the  stockholders  to
re-evaluate  the past  leadership  of Cortech and time to consider a change.  We
believe that Asset Value has the same interests as all other  stockholders which
it believes will be a change from this management - a substantial change.

PLEASE  ASK  YOURSELF:

DO YOU WANT THE BOARD MEMBERS WHO APPROVED THE
BIOSTAR MERGER TO SELECT THE NEXT MERGER  CANDIDATE
FOR  CORTECH?

WE THINK YOUR ANSWER WILL BE : CERTAINLY NOT!

     PLEASE SEND THE WHITE  PROXY CARD TO ASSET  VALUE AND VOTE TO INCREASE  THE
BOARD AND TO ELECT ALL OF ASSET VALUE'S NOMINEES.


                                            Sincerely,



                                            Paul O. Koether
                                            Asset Value Fund Limited Partnership
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        5 Market Watch, New York  Times,  3/8/98,  Floyd Norris.  This quote has
been made without the permission of the New York Times or Mr. Norris.





IT'S TIME FOR A CHANGE; VOTE FOR CHANGE;
VOTE FOR ASSET VALUE.

SEND IN THE WHITE PROXY CARD
VOTE YES TO INCREASE THE BOARD
VOTE FOR ALL OF ASSET VALUE'S NOMINEES
    

                                    IMPORTANT

     If your shares are held in "Street  Name" only your bank or broker can vote
your shares, and only upon receipt of your specific instructions. Please contact
the person  responsible  for your account and  instruct  them to execute a white
proxy card as soon as possible.

     If you have any questions or need further assistance in voting, please call
John W. Galuchie,  Jr., of Asset Value Fund Limited Partnership collect at (908)
234-1881, or our proxy solicitor:

                           BEACON HILL PARTNERS, INC.
                                 90 BROAD STREET
                            NEW YORK, NEW YORK 10004
                                 (800) 253-3814