Composition of Single-step Media Used for Human Embryo Culture

Objective: To determine compositions of commercial single-step culture media and test with a murine model whether differences in composition are biologically relevant.

Design: Experimental laboratory study.

Setting: University-based laboratory.

Animal(s): Inbred female mice were superovulated and mated with outbred male mice.

Intervention(s): Amino acid, organic acid, and ions content were determined for single-step culture media: CSC, Global, G-TL, and 1-Step. To determine whether differences in composition of these media are biologically relevant, mouse one-cell embryos were cultured for 96 hours in each culture media at 5% and 20% oxygen in a time-lapse incubator.

Main Outcome Measure(s): Compositions of four culture media were analyzed for concentrations of 30 amino acids, organic acids, and ions. Blastocysts at 96 hours of culture and cell cycle timings were calculated, and experiments were repeated in triplicate.

Result(s): Of the more than 30 analytes, concentrations of glucose, lactate, pyruvate, amino acids, phosphate, calcium, and magnesium varied in concentrations. Mouse embryos were differentially affected by oxygen in G-TL and 1-Step.

Conclusion(s): Four single-step culture media have compositions that vary notably in pyruvate, lactate, and amino acids. Blastocyst development was affected by culture media and its interaction with oxygen concentration.