Embryonic stem cells ESCs , derived from the blastocyst stage of early mammalian embryos, are distinguished by their ability to differentiate into any cell type and by their ability to propagate. A portion of stem cell researchers use embryos that were created but not used in in vitro fertility treatments to derive new stem cell lines. The extracted inner cell mass was cultured on fibroblasts treated with mitomycin-c in a medium containing serum and conditioned by ES cells. Routine tests in pregnancy. Others feel that a blastula is not exactly a child just yet, because unless a blastula is imbedded in the uterus wall, it will never have the chance to develop into a baby. With there being no true guidelines set forth in the Qur'an against the study of biomedical testing, Muslims have adopted any new studies as long as the studies do not contradict another teaching in the Qur'an. Compared with embryonic stem cells, adult stem cells have a more limited ability to give rise to various cells of the body.