Factors influencing murine embryo bioassay: effects of proteins, aging of medium, and surgical glove coatings

Abstract

The 2-cell murine embryo bioassay as quality control for human in vitro fertilization (IVF) was used to evaluate the effects of protein supplements, medium aging, and surgical glove coatings. Ham's F-10 medium (GIBCO, Grand Island, NY) without protein supplementation supported growth of the 2-cell embryos to blastocysts. Addition of bovine serum albumin (BSA), fetal cord serum (FCS), or maternal serum (MS) did not enhance or reduce the blastulation rates (medium alone, 89.4%; BSA, 86.4%; FCS, 90%; MS, 74.7%). Unsupplemented Ham's F-10 medium was found to contain three major peaks of approximately 50,000 daltons and several minor peaks, analyzed on high-performance liquid chromatography (HPLC) and sodium sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), suggesting the presence of protein(s) in the medium itself. The storing of medium up to 425 days at 4 degrees C affected neither the HPLC profile nor its ability to support embryo growth (blastulation rates: fresh, 84%; stored 150 to 425 days, 77.7%). The coating of surgical gloves affected embryo growth. Both talc-coated (TC) and "talc-free," starch-coated (SC) surgical gloves were found to be progressively embryotoxic when they touched the medium for increasing lengths of time, compared with uncoated latex (UL) gloves and untouched control medium. Quality control of medium preparation and handling in murine embryo bioassay is reemphasized, with requirements for protein supplementation, use of fresh medium, and possible contamination with even talc-free, SC surgical gloves reevaluated.