Objective
To evaluate the degree of enrichment of spermatogonial stem cells (SSCs) from human testicular cell cultures by ITGA6+, HLA-/ITGA6+, GPR125+, and HLA-/GPR125+ magnetic-assisted cell sorting (MACS). Design: Experimental basic science study. Setting: Reproductive biology laboratory. Patient(s): Multiple samples of cryopreserved human testicular cells from two prostate cancer patients with normal spermatogenesis. Intervention(s): Cultured human testicular cells subjected to four sorting strategies based on MACS and xenotransplanted to the testes of mice to determine the enrichment for SSCs. Main outcome measure(s): Enrichment for human spermatogonia and SSCs tested by expression analysis of spermatogonial markers ITGA6, GPR125, ZBTB16, UCHL1, and ID4 using quantitative real-time polymerase chain reaction (qPCR) and by xenotransplantation into the testes of mice, respectively. Result(s): Compared with the nonsorted cultured testicular cells, only the ITGA6+ and HLA-/GPR125+ sorted cells showed enrichment for ID4. No difference in expression of ZBTB16 and UCHL1 was observed. Xenotransplantation of the sorted cell fractions showed a 7.1-fold enrichment of SSCs with ITGA6+.