>99% [HPLC]. Free 4MU < 100ppm.
alpha-L-Fucosidase substrate: D. Robinson and R. Thorpe, Clin. Chim. Acta, 55, 65 (1974). Identification of some slow growing mycobacteria: J.M. Grange and G. McIntyre, J. Appl. Bacteriol., 47, 285 (1979).