Both the antiserum and IgG fractions of anti-Dextranase (Penicillium) are shown to detect under reducing conditions of SDS-PAGE the 41,000 dalton enzyme in cellular extracts. Approximately 10 ug of total protein is loaded per lane. A 1:2,000 dilution of the primary antibody is used followed by detection using HRP Goat-a-Rabbit IgG [H&L] diluted 1:4,000 and color development using 4-CN substrate until sufficient color develops. Other detection systems will yield similar results.