Albumin protection of mouse morulae and early blastocysts against the toxic effects of cuprous and cupric ions during development in vitro.

Concentrations of cuprous and cupric chloride of 50 micrometer or greater completely inhibited the development of mouse morulae and early blastocysts into blastocysts in vitro. The zona pellucida was completely dissolved at concentrations of 250 micrometer cupric and 500 micrometer cuprous ions. No significant difference in toxicity was found between the cuprous and cupric ion at 0-50 micrometer. The addition of protein, as BSA, to the culture medium partly protected the embryos against the toxic effect of both copper ions. At a concentration of 25 micrometer a significantly higher level of BSA was required to protect against the cupric than the cuprous ion. Increasing the concentration of either ion increased the level of BSA required to exert a protective effect.