Fig. 1From: In vitro transplantation of spermatogonial stem cells isolated from human frozen–thawed testis tissue can induce spermatogenesis under 3-dimensional tissue culture conditionsConfirmation of the identification of SSCs. The expression of PLZF protein in colonies obtained from culture of SCs (a) and SSCs on seminiferous tubules as positive control (d) phase contrast image (b, e), negative control group without primary antibody (c, f)Back to article page