You take a six to eight cell embryo, you tease out one of the cells, you run a genetic test on that cell, and depending on the results of that test you either implant that embryo or you discard it.
6から 8個ほどの胚細胞を取って 一つを遺伝子テストにかけ その結果次第で 胚を移植あるいは破棄します