Minimum essential medium alpha (MEM) enhances assisted reproductive technology results. I. Mouse embryo study

Our purpose was to find a medium to enhance mouse zygote development and, hopefully, to apply the results to a coculture system and to enhance the ART pregnancy rate.

The study was designed to compare different media's support of mouse zygote development with/without serum supplement. The outcome measure was the percentage of mouse zygotes/embryos that developed to the expanded blastocyst and hatchout stage.

(1) Using human tubal fluid (HTF), one-cell zygotes had a 34.6 +/- 5.2% (mean +/- standard deviation) development rate, and two-cell embryos a 86.5 +/- 3.2% development rate. (2) Minimum essential medium alpha (MEM) showed the best results (52.2 +/- 14.5%) among Ham's F-10 (19.1 +/- 6.3%), HTF (26.8 +/- 8.2%), NCTC-135 (38.8 +/- 12.6%), MEM with nuclei acid (24.6 +/- 10.0%), and Dulbecco's modified Eagle medium (28.0 +/- 20.2%). (3) With the serum supplement, there was no significant difference among Ham's F-10 (21.5 +/- 23.7), HTF (29.3 +/- 10.4%), NCTC-135 (36.5 +/- 6.2%), and MEM (38.8 +/- 17.9%).

MEM is the best medium among the six media examined. Preliminary study showed that MEM gave a good clinical pregnancy rate (29%).