Preservation of murine embryos in a state of dormancy at 4C

With the aim ofimproving preservation of blood products and organs fortransplantation, we designed solutions to induce a state of dormancy incells and tissues at 4°C. The solutions were devoid of combinationsof ions (e.g., K⁺,Rb⁺,Cs⁺, andNH⁺₄ withHCO₃,H₂PO₄, andCl) that are believed tobreak down low-density water in the entrance compartments of ionchannels, resulting in cyclical open states (normal water) and closedstates (low-density water). The total osmolality was always0.29-0.3 osmol/kgH₂O, made upof combinations of a di- or trisaccharide, a compatible solute, sodiumsulfate, citrate, or chloride, and 1.75 mMCaCl₂. The end point was the ability of murine embryos to progress to hatching in culture after preservation in such a solution at 4°C. Embryos hatched after 5 or6 days in some preservative solutions compared with 1-3 days inmost saline solutions; survival was improved by pretreatment withsodium butyrate.