Survival of frozen-thawed mouse and rat embryos in the presence of ethylene glycol

Abstract

Survival of mammalian embryos after storage at very low temperatures was first achieved in the mouse with suitably slow rates of cooling and thawing and in the presence of the dimethyl sulphoxide (DMSO) or glycerol (Whittingham, Leibo & Mazur, 1972; Wilmut, 1972; Leibo, Mazur & Jackowski, 1974). Similar procedures have been applied for the embryos of cattle (Wilmut & Rowson, 1973), rabbit (Bank & Maurer, 1974; Maurer & Haseman, 1976), rat (Whittingham, 1975), and sheep (Willadsen, Polge, Rowson & Moor, 1976) in the presence of DMSO. A report (Whittingham, 1971a) of the survival of mouse embryos frozen and thawed in medium containing polyvinylpyrrolidone (PVP) has not been confirmed (Whittingham et al., 1972; Wilmut, 1972) and no survival has been achieved for rabbit embryos frozen in the presence of PVP or glycerol (Bank & Maurer, 1974). Greater survival was obtained for mouse embryos frozen in the presence of DMSO than in glycerol (Whittingham et al., 1972). It therefore seems that DMSO is more effective than glycerol for the protection of mammalian embryos from freezing damage. This communication reports the survival of mouse and rat embryos after freezing and thawing by using ethylene glycol as the cryoprotective agent.