Nonfreezing technique for short-term storage of mouse embryos.

Mouse morulae were stored at 0 degrees C in the medium containing various sugars, and their effect on the embryonic viability was examined. The longevity of the embryos was considerably extended, if a hexose or a disaccharide was supplemented in the medium. The most effective concentration appeared to be 0.5-0.75 M, irrespective of the molecular weight. Glucose, galactose, fructose, sucrose and lactose were more effective than mannose and maltose. Considering that the embryos stored with sugars were recovered shrunken, the beneficial effect of sugars seemed to be from proper dehydration of the cells caused by osmotic pressure afforded by a non-toxic and non-permeable non-electrolyte. The non-freezing technique using a sugar could also be used combined with a freezing technique, if 1-6 h of incubation is incorporated between the two treatments. If the non-freezing technique prove to be available to the embryos of domestic animals, it will practically be more useful.