Antisticking protein factors in buffalo blood serum

Buffalo blood serum is a potent source of antisticking factor (ASF) that inhibits with high affinity adhesion of goat epididymal spermatozoa to the glass surface of hemocytometer counting chamber. The serum is also capable of inhibiting glass-sticking of spermatozoa of the buffalo, ram, and bull. The serum ASF activity is nondialyzable and stable to heat treatment at 100 degrees C for two minutes. The activity of the serum ASF was lost completely when treated with trypsin (50 micrograms/ml) at 37 degrees C for thirty minutes indicating the polypeptide nature of the ASF. Serum ASF activity consists of at least two factors (A and B) as shown by concanavalin A-agarose affinity chromatography. ASF-A and -B represent nearly 75% and 25% of the total serum ASF activity. ASF-B is a glycoprotein as it binds with high affinity to concanavalin A. The sera of species such as man, goat, and rat possess ASF activity.