Globulins in protein supplements promote the development of preimplantation embryos

Purpose: Our purpose was to investigate the effect of alpha-and beta-globul ins contained in protein supplements on the development of preimplantation embryos. Methods: Mouse one-cell embryos were cultured in medium supplemented with 4 mg/ml human serum albumin (HSA), 4 mg/ml HSA plus human globulins (0.2, 0. 4, 0.8, and 1.6 mg/ml) that consisted predominantly of alpha- and beta-glob ulins, or 10% Plasmanate Cutter (PC). Blastocysts developed in media supple mented with these various protein sources were stained with Hoechst 33342 t o determine the number of cells. Results: Supplementation with 0.4 to 1.6 mg/ml globulins or PC significantl y increased the rate of blastocyst development compared with that observed with the addition of HSA. Supplementation with globulins significantly incr eased the hatching rate in a dose-dependent manner: The number of cells in the blastocysts was significantly increased when the embryos were cultured with 0.8 mg/ml of the globulins or PC. Conclusions: The present observations suggest that alpha- and beta-globulin s in protein supplements promote embryo development and hatching.