Hydrolysis reaction is caused by making protease act on methylcoumarin-amide (mca) of peptide substrate, and 7-amido-4-methylcoumarin (AMC) isolated. This isolated AMC, fluorescence becomes the maximum by wavelength 440 nm. Protease activity can be measured using fluorescence spectrophotometer.

Jasco introduces an example in which the activity measurement of trypsin was performed using a fluorescence peptide MCA substrate.