REVISED PRELIMINARY OPPOSITION PROXY MATERIAL

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



                                                                    July__, 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  Asset Value's  nominees
would  provide  better  leadership  for  Cortech  and that is why we are seeking
control of the Board by electing our nominees to the Board.1

     Effective  July 21, 1998,  three members of the old Board (the "Old Board")
resigned after appointing their  replacements (the "Appointed  Board").  Cortech
has stated  that the  departures  did not  result  from  disagreements  with the
Company.  There has been no explanation of why the incumbents did not wait until
their successors were chosen by the stockholders on September 4 which would have
permitted stockholders an opportunity to elect the new Directors.

   WARNING: "Those who cannot remember the past are condemned to repeat it."2

     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 Old  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 Old  Board  from the  start  that the  Merger  was not in the
interests of stockholders3 who, Asset
- --------
     1    Asset Value is also asking stockholders to approve an amendment to the
By-laws which would increase the number of directors from four to seven creating
a total of four vacancies (the "Board  Amendment").  If these four vacancies are
filled with Asset  Value's  nominees,  control of Cortech will transfer to Asset
Value.  If the Board is not  increased,  Asset Value will seek to elect  nominee
Paul  Koether,  to fill the vacancy  which would then be  available.  Management
opposes the Board  Amendment and instead  proposes to amend the  Certificate  of
Incorporation so that only directors have a right to set the number of directors
(the "Elimination of Stockholders Right").  Asset value opposes the Elimination
of Stockholders Right.

     2    The Life of Reason, (1905) George Santayana

     3    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.






Value said, would never approve such a transaction.  The Merger was canceled  on
May 7, 1998.

          ONLY ASSET VALUE WAS WILLING TO SPEND ITS TIME AND MONEY TO
                          PUBLICLY OPPOSE THE MERGER!
    

We ask you. Do you want Cortech led into the future by any incumbent Director or
                   any other nominee connected to this past?

                              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 full-time4  employees and
general  and  administrative  expenses of  $1,522,000,  of which,  according  to
Cortech,  merger expense only accounted for  approximately  $673,000.  After the
Form10-Q was filed 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.  The  calculation  of the $500,000
departure  bonus was  derived by adding 20 months of salary  ($442,000),  future
consulting fees of an undisclosed  amount and health  insurance  coverage for 18
months estimated at $600 per month as reported in Cortech's Form 8-K filed on
May 18, 1998.

   
                         What did the Old Board do next?

     Well one thing it did not do -at least not voluntarily- is call this Annual
Meeting within the 13 months  required by Delaware law.  Instead Asset Value had
to file a  lawsuit  to  compel  the Board to let  stockholders  decide  who will
determine  Cortech's  future.  THIS MEETING WAS ORDERED BY THE CHANCERY COURT OF
DELAWARE ONLY AFTER A LAWSUIT WAS FILED BY ASSET VALUE TO COMPEL A MEETING.
    
- --------
     4    Cortech  does not  disclose  whether  there are  additional  part-time
employees and consultants  still hanging on. 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, there is no assurance that Cortech would be shut down.






   
     Ask yourself why would the Old Board spend Cortech's  limited  resources to
defend  against a demand to hold an annual  meeting as required by law?  And why
would the  Appointed  Board  spend  Cortech's  limited  resources  on this proxy
contest?

     We think one  reason is  because  management  does not want you to ask this
question:
    

                 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 NASDAQ BIOTECHNOLOGY INDEX (IXBT)
                                     AND THE
                AMERICAN STOCK EXCHANGE BIOTECHNOLOGY INDEX (BTK)


                               [GRAPH THE ABOVE]




               Cortech         IXBT        BTK
               ------          -----      ------
                                    
1993          $18.25          197.88      115.78

1994           14.25          161.40       82.06

1995            3.65625       304.30      133.77

1996            3.8125        314.48      144.56

1997            2.03125       304.89      163.28

7/17/1998        .50          335.15      144.16





                              NOT A PRETTY PICTURE!








                              TOO LITTLE, TOO LATE
   
     Seven  months after Asset Value first asked for  representation  on the Old
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
or committed  significant amounts of its own funds (estimated to exceed $125,000
including  counsel  fees and  management  time) in  opposing  the  Merger and in
securing  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 management would not embrace the necessary changes.  Asset Value thought that
the Old Board's offer to meet, in and of itself, was too little too late.
    

                  MANAGEMENT'S VERSION OF STOCKHOLDER DEMOCRACY
   
     Management  called  this  Meeting  only after Asset Value filed to have the
Delaware  courts  compel  Cortech  to hold the  Meeting.  We ask you:  Why would
management  fail to call a  meeting  within  the time  required  by law?  Why is
management  spending  your money and our money to delay what we believe  will be
the day of  reckoning  when  the  stockholders  will  finally  be given a choice
between what in our view,  is the failed past and what we think will be a better
future.  In making  this  choice,  we ask you to  consider  that Asset Value has
promised  not to seek to merge  Cortech  with any  affiliate  or entity in which
Asset Value is an investor.  Nor will Asset Value  consider  selling its Cortech
Stock before a transaction is  consummated  which Asset Value believes is in the
interests of all  stockholders.  Asset Value intends to benefit from its Cortech
investment only to the same extent other  stockholders  benefit.  Moreover Asset
Value's nominees do not intend to take any fees for managing Cortech.
    

                         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 $14.3 million.  We ask, does Lynn's departure absolve the
Old Board members of their  responsibility for these losses? We think the answer
is a resounding No!









Will you vote for the nominees appointed by the Old Board members who led us to
           where we are today? We hope the answer is a resounding No!



                  PICTURE OF HOUR GLASS WITH CONTENTS READING

                                                               CASH REMAINING AT
                                                               MARCH 31, 1998
                                                               $14.3 million





                                                               ACCUMULATED
                                                               DEFICIT
                                                               $86 million!!!

    



                          THE SHAPE OF THINGS TO COME 5

     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.


- --------
     5     H.G. Wells





   
     The  principal  standards  for seeking a candidate  would be balance  sheet
quality, positive earnings and good growth potential.  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.  As of March 31, 1998,  Cortech's
total assets were $14.9  million of which cash and cash  equivalents  were $14.3
million. 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.  Nor will Asset Value  consider  selling its Cortech
Stock before a transaction is  consummated  which Asset Value believes is in the
interests of all  stockholders.  Asset Value intends to benefit from its Cortech
investment only to the same extent other stockholders benefit.
    

     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 A BOARD COMPRISED OF ANY DIRECTORS WHO
                WERE PART OF MANAGEMENT WHILE CORTECH WAS LOSING
                                 ALL THIS MONEY?
    
               DO YOU WANT FUTURE TRANSACTIONS SELECTED BY ANYONE
              WHO EITHER APPROVED THE MERGER OR STOOD SILENT WHILE
                            THE MERGER MOVED FORWARD?

                  WE HOPE YOUR ANSWER WILL BE : CERTAINLY NOT!
   
              PLEASE SEND THE GREEN PROXY BALLOT TO ASSET VALUE AND
              VOTE TO INCREASE THE BOARD AND TO ELECT ASSET VALUE'S
                                    NOMINEES.
    
                    IT'S TIME FOR A CHANGE; VOTE FOR CHANGE;
                              VOTE FOR ASSET VALUE.
   
                       SEND IN THE GREEN PROXY BALLOT VOTE
                   YES TO INCREASE THE BOARD BUT IN ANY EVENT:
    







                     VOTE FOR ALL OF ASSET VALUE'S NOMINEES!
   
              VOTE AGAINST THE ELIMINATION OF A STOCKHOLDERS RIGHT!
    

                                            Very truly yours,



                                            Paul O. Koether
                                            Asset Value Fund Limited Partnership




                                    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 Green
Proxy Ballot 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