Supplementary Table S7. Derivation of ES cells from twin blastocysts after ICSI and NF.

Embryos were produced using spermatozoa of the OG2 strain. Blastocysts were plated on feeder layer to allow for outgrowth formation and ES cell derivation. Pluripotent colonies were visualized by Oct4-GFP fluorescence and counted using an Operetta high-content imager, keeping track of the fertilization method (ICSI or natural fertilization, NF), of the site of the ICSI (contralateral, ipsilateral, equatorial), and of the original pair associations (twin, cotwin).