Optimization of teratoma formation assay

Abstract

Teratoma formation assay is necessary to estimate in vivo pluripotency of stem cells especially stem cell lines of human origin. Nevertheless convenient, valid and universal “standards” to analyze stem cell derived tumors have not been developed yet. New protocol for monitoring teratoma growth, morphological and histological analyzes of tumor samples is proposed in this paper. This protocol is oriented on review of tumors morphology and histology per se. The list-describer includes 17 obligate and 12 facultative diagnostic sell types and 7 diagnostic cell complexes. The protocol takes into account complicity and heterogeneity of teratoma structure and allows detect different morphological features of malignization process inside stem cell derived tumors in situ. The protocol was successfully applied for teratoma formation test which has been performed for 52 stem cell lines of different species origin (mouse, rat, аmerican mink and human). 326 stem cell derived tumors were completely described, reviewed and analyzed.