>97% [HPLC]. Free 4MU < 200ppm.
Detection of N-acetyl-beta-D-galactosaminidase in tissues: B.G. Winchester, Biochem. J., 124, 929 (1971). Rapid identification of Candida albicans: M.T. Dalton et al., Diagn. Microbiol. Infect. Dis., 12, 521 (1989).