Standardization of the teratoma assay for analysis of pluripotency of human ES cells and biosafety of their differentiated progeny. oleh Michal Gropp, Vitali Shilo, Gilad Vainer, Miri Gov, Yaniv Gil, Hanita Khaner, Limor Matzrafi, Maria Idelson, Juri Kopolovic, Naomi B Zak, Benjamin E Reubinoff