<PAGE>   1
                                                                      Exhibit 24


                                POWER OF ATTORNEY



         KNOW BY ALL MEN BY THESE PRESENTS, that the undersigned director of
Demegen, Inc., a Colorado Corporation, does make, constitute and appoint RICHARD
D. EKSTROM, with full power and authority his true and lawful attorney-in-fact
and agent, for him and his name, place and stead in any and all capacities, to
sign the Annual Report of Demegen, Inc. on Form 10-KSB for the year ended
September 30, 1999, and to file such Annual Report, so signed, with all exhibits
thereto, with the Securities and Exchange Commission, hereby further granting
unto said attorney-in-fact full power and authority to do and perform any and
all acts and things requisite and necessary to be done in and about the premises
as fully to all intents and purposes as he might or could do in person; the
undersigned hereby ratifies and confirms all that said attorney and agent, shall
do or cause to be done by virtue hereof.


         IN WITNESS WHEREOF, THE UNDERSIGNED HAS HEREUNTO SET HIS HAND AND SEAL
THIS 2nd day of December, 1999.







   /s/ James Colker   (SEAL)
----------------------
James Colker, Director



<PAGE>   2


                                POWER OF ATTORNEY



         KNOW BY ALL MEN BY THESE PRESENTS, that the undersigned director of
Demegen, Inc., a Colorado Corporation, does make, constitute and appoint RICHARD
D. EKSTROM, with full power and authority his true and lawful attorney-in-fact
and agent, for him and his name, place and stead in any and all capacities, to
sign the Annual Report of Demegen, Inc. on Form 10-KSB for the year ended
September 30, 1999, and to file such Annual Report, so signed, with all exhibits
thereto, with the Securities and Exchange Commission, hereby further granting
unto said attorney-in-fact full power and authority to do and perform any and
all acts and things requisite and necessary to be done in and about the premises
as fully to all intents and purposes as he might or could do in person; the
undersigned hereby ratifies and confirms all that said attorney and agent, shall
do or cause to be done by virtue hereof.


         IN WITNESS WHEREOF, THE UNDERSIGNED HAS HEREUNTO SET HIS HAND AND SEAL
THIS 2nd day of December, 1999.







    /s/ Robert E. Hannan  (SEAL)
--------------------------
Robert E. Hannan, Director



<PAGE>   3



                                POWER OF ATTORNEY



         KNOW BY ALL MEN BY THESE PRESENTS, that the undersigned director of
Demegen, Inc., a Colorado Corporation, does make, constitute and appoint RICHARD
D. EKSTROM, with full power and authority his true and lawful attorney-in-fact
and agent, for him and his name, place and stead in any and all capacities, to
sign the Annual Report of Demegen, Inc. on Form 10-KSB for the year ended
September 30, 1999, and to file such Annual Report, so signed, with all exhibits
thereto, with the Securities and Exchange Commission, hereby further granting
unto said attorney-in-fact full power and authority to do and perform any and
all acts and things requisite and necessary to be done in and about the premises
as fully to all intents and purposes as he might or could do in person; the
undersigned hereby ratifies and confirms all that said attorney and agent, shall
do or cause to be done by virtue hereof.


         IN WITNESS WHEREOF, THE UNDERSIGNED HAS HEREUNTO SET HIS HAND AND SEAL
THIS 2nd day of December, 1999.







        /s/ Jerry B. Hook          (SEAL)
----------------------------------
Jerry B. Hook, Ph.D., Director




<PAGE>   4



                                POWER OF ATTORNEY



         KNOW BY ALL MEN BY THESE PRESENTS, that the undersigned director of
Demegen, Inc., a Colorado Corporation, does make, constitute and appoint
RICHARD D. EKSTROM, with full power and authority his true and lawful
attorney-in-fact and agent, for him and his name, place and stead in any and all
capacities, to sign the Annual Report of Demegen, Inc. on Form 10-KSB
for the year ended September 30, 1999, and to file such Annual Report,
so signed, with all exhibits thereto, with the Securities and Exchange
Commission, hereby further granting unto said attorney-in-fact full power and
authority to do and perform any and all acts and things requisite and necessary
to be done in and about the premises as fully to all intents and purposes as he
might or could do in person; the undersigned hereby ratifies and confirms all
that said attorney and agent, shall do or cause to be done by virtue hereof.


         IN WITNESS WHEREOF, THE UNDERSIGNED HAS HEREUNTO SET HIS HAND AND SEAL
THIS 2nd day of December, 1999.







        /s/ Jesse M. Jaynes     (SEAL)
--------------------------------
Jesse M. Jaynes, Ph.D., Director

<PAGE>   5






                                POWER OF ATTORNEY



         KNOW BY ALL MEN BY THESE PRESENTS, that the undersigned director of
Demegen, Inc., a Colorado Corporation, does make, constitute and appoint
RICHARD D. EKSTROM, with full power and authority his true and lawful
attorney-in-fact and agent, for him and his name, place and stead in any and all
capacities, to sign the Annual Report of Demegen, Inc. on Form 10-KSB
for the year ended September 30, 1999, and to file such Annual Report,
so signed, with all exhibits thereto, with the Securities and Exchange
Commission, hereby further granting unto said attorney-in-fact full power and
authority to do and perform any and all acts and things requisite and necessary
to be done in and about the premises as fully to all intents and purposes as he
might or could do in person; the undersigned hereby ratifies and confirms all
that said attorney and agent, shall do or cause to be done by virtue hereof.


         IN WITNESS WHEREOF, THE UNDERSIGNED HAS HEREUNTO SET HIS HAND AND SEAL
THIS 2nd day of December, 1999.






    /s/ John Bridwell  (SEAL)
-----------------------
John Bridwell, Director


<PAGE>   6






                                POWER OF ATTORNEY



         KNOW BY ALL MEN BY THESE PRESENTS, that the undersigned director of
Demegen, Inc., a Colorado Corporation, does make, constitute and appoint
RICHARD D. EKSTROM, with full power and authority his true and lawful
attorney-in-fact and agent, for him and his name, place and stead in any and all
capacities, to sign the Annual Report of Demegen, Inc. on Form 10-KSB
for the year ended September 30, 1999, and to file such Annual Report,
so signed, with all exhibits thereto, with the Securities and Exchange
Commission, hereby further granting unto said attorney-in-fact full power and
authority to do and perform any and all acts and things requisite and necessary
to be done in and about the premises as fully to all intents and purposes as he
might or could do in person; the undersigned hereby ratifies and confirms all
that said attorney and agent, shall do or cause to be done by virtue hereof.


         IN WITNESS WHEREOF, THE UNDERSIGNED HAS HEREUNTO SET HIS HAND AND SEAL
THIS 2nd day of December, 1999.







      /s/ Konrad M. Weis       (SEAL)
-------------------------------
Konrad M. Weis, Ph.D., Director