Figure 2
The effect of O 2 tension on growth rate. Hybrid strain zygotes were cultured as 10 embryos in a drop of 10 μL GE-HTF medium, sIVF or KSOM media. The rates of blastocyst formation (A) 96 h and (B) 116 h post-HCG, (C) the rate of hatching blastocysts and (D) the cell number in the resultant blastocyst (116 h post-hCG) were analysed. Each treatment contained at least 80 embryos from two independent replicates. *p < 0.001, compared to the embryos cultured in 20% O2. **p < 0.001, compared to modHTM or KSOM media in 5% O2. (E) Representative images of embryos developed in different O2 tension stained with Hoechst 33342 and examples of fragmented nuclei shown with arrows.