Japanese Journal of Veterinary Research;Volume 37, Number 2

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EFFECTS OF VARIOUS CRYOPROTECTANTS ON THE SURVIVAL OF MOUSE EMBRYOS CRYOPRESERVED BY THE QUICK FREEZING METHOD

ABAS MAZNI, Othman;TAKAHASHI, Yoshiyuki;VALDEZ, Conrado A.;HISHINUMA, Mitsugu;KANAGAWA, Hiroshi

Permalink : http://hdl.handle.net/2115/3139
KEYWORDS : embryo;cryoprotectant;lactose;sucrose;quick freezing

Abstract

The effects of concentrations of glycerol, ethylene glycol or dimethylsulphoxide (DMSO) in the presence of either 0.25M lactose or sucrose on the post-thaw survival of mouse quickly-frozen compacted morulae were studied. In this method, the embryos were directly frozen in liquid nitrogen (LN_2) vapor at approximately -170℃ for 2 min before being plunged into LN_2. High survival rates of frozen-thawed embryos were obtained when the freezing medium contained 3M ethylene glycol with either 0.25M lactose or sucrose (76.5 and 70.2%, respectively). When the embryos were frozen in glycerol, significantly high survival was obtained with 3M glycerol+0.25M sucrose (73.5%, P<0.001). However, a freezing medium containing DMSO with either sugar gave lower survival rates. At a higher concentration of 4M, ethylene glycol with 0.25M lactose gave significantly higher survival rate than glycerol or DMSO (P<0.05). Significantly higher rates were obtained at 2M with all 3 cryoprotectants when the freezing medium containe lactose rather than sucrose (P<0.05). This study showed that glycerol and ethylene glycol were effective cryoprotectants in the quick freezing of mouse embryos, while DMSO was less effective. In addition, the protective effects of these cryoprotectants are affected by their concentrations and the type of sugar used.

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