All rights of reproduction in any form reserved. Capacitation of Large Numbers of Hamster Sperm in Vitro

A test tube system that capacitates large numbers of hamster sperm is described in detail. The 1-mi capacitating media contained heat-detoxified human serum or a dialysate of human serum to which human serum albumin had been added. Up to 2.5>< 10’ sperm were incubated therein for 4 h at 37#{176}C in the absence of mineral oil and ova. When aliquots of these sperm were combined with ova and the ova were examined 1-2 h later, up to 100 % contained swelling sperm heads within them. Fertilization was often polyspermic. After the 4 h capacitation incubation, up to 60 % of the motile sperm were without acrosomes, suggesting a high capacitation elficiency. This macrocapacitation system has proved useful in the clarification of certain biochemical events in sperm capacitation. A key event in mammalian conception is the maturation of sperm within the fe-male through a little understood process called capacitation (Austin, 1951; Chang, 1951; Bedford, 1970). Without this step