A system is used for determining efficacy of a sterilization cycle. A biological sterility indicator exhibits fluorescence in response to biological activity which is indicative of bacterial growth in the biological sterility indicator. The biological sterility indicator is exposed to the sterilization cycle and is placed in a fluorescence reading apparatus. The fluorescence from the biological sterility indicator is read to obtain a first fluorescence reading. The fluorescence from the biological sterility indicator is re-read to obtain a second fluorescence reading. The efficacy of the sterilization cycle is determined based on the first and second fluorescence readings.