Optimized culture systems for the preimplatation ICR mouse embryos with wide range of EDTA concentrations

In this study, in vitro preimplantation embryo culture media especially for outbred stock mice (Institute of Cancer Research (ICR)) were optimized with different concentrations of Ethylenediaminetetraacetic acid (EDTA). A plot with embryo development rates against EDTA concentrations ranging from 0 to 500µM showed a unique pattern with two characteristic peaks. 200µM was adopted as an optimal concentration of EDTA. The optimized media were also evaluated with two culture systems; conventional large volume culture system (1ml) and micro-droplet culture system. In the conventional large volume culture system, the blastocyst development rates were compared among three different media (F-10, KSOM and KSOM with the optimized 200µM EDTA). The rates were 0.4%, 16.7% and 57.6%, respectively. The development rates for micro-droplet (10µl) culture system was 73.9%. In conclusion, 200µM EDTA concentration in 10µl droplets in the KSOM medium was found as most suitable culture conditions for ICR mouse embryos as the blastocyst development rate was higher in micro-droplet culture system than in the traditional conventional large volume culture system.