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                         SPECIAL POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that the undersigned, constitutes and
appoints JOSEPH HINES and BRADLEY C. ANDERSON as his true and lawful
attorney-in-fact and agent with full power of substitution and resubstitution,
for him and his name, place and stead, in any and all capacities, to sign the
Annual Report on Form 10-K for fiscal year ended July 31, 2000, for filing with
the Securities and Exchange Commission by Zila, Inc., a Delaware corporation,
together with any and all amendments to such Form 10-K, and to file the same
with all exhibits thereto, and all documents in connection therewith, with the
Securities and Exchange Commission, granting to such attorney-in-fact and agent,
full power and authority to do and perform each and every act and thing
requisite and necessary to be done in and about the premises, as fully and to
all intents and purposes as he might or could do in person, hereby ratifying and
confirming that such attorney-in-fact and agent, may lawfully do or cause to be
done by virtue hereof.

     DATED:  October 27, 2000

                                             /s/ Christopher D. Johnson
                                             --------------------------
                                             CHRISTOPHER D. JOHNSON

STATE OF ARIZONA    )
                    )
County of Maricopa  )

     On the 27th day of October, 2000, before me, the undersigned Notary
Public, personally appeared CHRISTOPHER JOHNSON, known to be the person whose
name Is subscribed to the within instrument and acknowledged that he executed
the same for the purposes therein contained.

     IN WITNESS WHEREOF, I hereunto set my hand and official seal.

                                             /s/ Janice L. Backus
                                             --------------------------
                                             Notary Public


My commission expires:
[seal of Janice L. Backus]

                                       EXHIBIT
                                        24-F