Figure 1.

Physiologic Spermatogonial apoptosis in the adult rat testis. (A) Example of spermatogonia undergoing apoptosis (arrow) in rat testis under normal physiological conditions. Insert (magnification 300x) demonstrates the distinct features of DNA fragmentation, blebbing and darkly stained nuclei. The testis was immersion fixed in Bouins, embedded in Glycol methacrylate and 3 μm sections stained with periodic acid-Schiff's reagent and hematoxylin. (B) Example of TUNEL positive cells undergoing apoptosis in the normal adult rat testis (arrows). The testis was immersion fixed in Bouin's, embedded in paraffin and 5 μm sections stained with Apoptag kit (Millipore Cat #S-7001).