Figure 4From: Isolation and characterization of human spermatogonial stem cellsSSCs observed under inverted phase contrast microscope at different times. a, b, c: SSCs at 48 h of culture on the feeder layer of Sertoli cells (×100, ×200, ×400, respectively); d: SSCs at 30 days of culture on the feeder layer of Sertoli cells (×100).Back to article page