However, since the generation of embryonic stem cells involves destruction (or at least manipulation) of the pre-implantation stage embryo, there has been much controversy surrounding their use.
Namun, karena generasi sel punca embrionik melibatkan penghancuran (atau setidaknya manipulasi) dari embrio tahap pra-implantasi, ada banyak kontroversi seputar penggunaannya.