2.6 Isolation of human and mouse spermatogenic cells
Spermatogenic cells were obtained through cell diameter/density at unit gravity using the STA-PUT velocity sedimentation method. In brief, human and mouse germ cells were extracted from the testicular biopsy tissues of male adults and adult C57BL/6 male mice. Next, spermatogenic cells were resuspended in 25 ml of 0.5% BSA solution and filtered through an 80 mm mesh to remove cell aggregates. After passage through a mesh filter, the cells were resuspended in buffer containing 0.5% BSA and loaded in an STA-PUT velocity sedimentation cell separator (ProScience) for gradient separation. Several germ cell populations were collected for subsequent analysis.