The EnzChek® Peptidase/Protease Assay Kit provides a FRET-based substrate comprised of a fluorophore and quencher moiety separated by a short amino acid sequence. Upon cleavage by proteases, the fluorophore seaprates from the quencher and is free to emit a detectable fluorescent signal (excitation/emission maxima ~502/528 nm). The assay is performed in a simple mix-incubate-read format, can be completed in 60 miunutes or less and is easily adaptable to accomodoate diverse pH requirements.