Following the early reports by Barraquer 1 and Jenkins 2 on the use of α-chymotrypsin in cataract surgery, ophthalmic surgeons have shown considerable interest in the further development of this new technique. This communication details results that indicate by both biochemical assay and clinical experience, at least one commercial α-chymotrypsin preparation * can be used repeatedly after solubilization as a chemical adjunct to cataract surgery. Experimental Results The enzyme preparation was solubilized with its accompanying diluent as per manufacturer's directions to give a 1:5,000 dilution (stock enzyme solution). All aliquot removals were performed aseptically. In these experiments 2 separate samples of α-chymotrypsin were used; one for stability studies at 25 C and the other for comparable purposes at 2 C. Residual enzymatic activity was determined at pH 8.0 and 30 C with either N -carbobenzoxy-l-tyrosine p -nitrophenyl ester (CTN) or N -acetyl-ltyrosine ethyl ester (ATEE) as substrates.