Figure 6: Immunogold staining of rat epididymal sperm with monoclonal antibody 3#-1. Control sections (a, c, and e) showing the sperm nucleus and flagella stained with secondary antibody only. Specific staining of the epitope was observed in the sperm nucleus (b) and outer dense fibers in the transverse (d) and longitudinal (f) sections. Scale bars, 500 nm. N: Nucleus.