Effect of variable concentration of serum on mouse embryo development.

This study was undertaken to determine the optimal concentration of serum necessary for maximal embryo development. Mouse embryos were cultured in vitro with 0% to 30% concentrations of serum of 96 hours. After 72 and 96 hours of culture, embryo growth was improved with 5%, 10%, 20%, and 30% serum supplement when compared with Ham's F-10 medium alone. Embryos were then cultured with the same concentrations of serum for 29 hours, following which blastomere number, sister chromatid exchange (SCE), number of micronuclei, and chromosomal aberrations were observed. There was no difference in blastomere number with any concentration of serum supplement studied. All concentrations of serum decreased the number of SCE when compared with Ham's F-10 medium alone. The rate of SCE in embryos cultured with 10%, 20%, or 30% serum was also smaller than that of the embryos cultured with 5% serum. The results of these studies indicate that serum should be employed for culturing embryos, and at least 10% serum concentration is necessary to obtain optimal conditions for embryo development.