The immobilization of spermatozoa by freezing and thawing and the protective action of glycerol

Abstract

Spermatozoa of the rabbit, the bull, the fowl and the herring were subjected to freezing and thawing in media containing various concentrations of glycerol, and observations made of the resulting changes in motility. These observations indicated that the damage suffered by the spermatozoa during freezing and thawing was caused by their exposure to excessive concentrations of salt when water was removed as ice. The concentrations of electrolyte above which irreversible damage occurred was characteristic for the spermatozoa of each species tested. The protective action of glycerol was due to its ability to prevent the salt concentration rising above this level.