The present invention relates to methods of measuring the activity of a hydrolytic agent comprising contacting a biomolecule with a hydrolytic agent in the presence of a fluorescent dye under conditions that allow digestion of the biomolecule by the hydrolytic agent. The fluorescence of the dye is monitored over time and a change in fluorescence signifies digestion of the biomolecule by the hydrolytic agent. The biomolecule is preferably a protein, peptide or proteome but can also be a carbohydrate, oligonucleotide or lipid. Further methods relate to determining an end point for digestion of a biomolecule by a hydrolytic agent, and methods of monitoring digestion of a biomolecule by a hydrolytic agent. The monitoring can be performed on the reaction mixture in real time or via sampling. The invention also relates to kits for carrying out the method.