Improvedlysozymeassay in Biologicalfluids Materials and Methods

We describe a simple, rapid, sensitive, and highly reproducible assay for lysozyme, with use of concentrated cell suspensions of Micrococcus Iysodeikticus in Tris-buffered glycerol/water (40/60 by vol), pH 7.5. Stored at -20 #{176}C, the cells’ susceptibility to lysozyme remains unaltered over long periods. Almost identical concentration curves were obtained with different aliquots of the same preparation during eight months. Lysozyme activity was reflected in the decrease in absorbance of the reaction mixture after incubation for 15 mm at 37 #{176}C. Concentrations of eggwhite lysozyme as low as 0.02 mg/L can be accurately assayed.