“…Blastocyst vitrification was performed following our previously reported procedure (24,25), based on the method of Yokota and co-workers (26), with some minor modifications. In short, 16 day-5, abnormal blastocysts were placed for 2 minutes in 1 mL of Dulbecco phosphate-buffered saline solution supplemented with 20% (v/v) serum (hereafter s-PBS).…”