Figure 2

Cryostat sections of rat seminiferous tubules cultured for 48 h without further treatment, to indicate the integrity of all spermatogenic stages after such incubation. A. Indirect Cy3 immunofluorescence for ELP protein (red); all nuclei are stained using DAPI (blue). Note the persistence of large numbers of positively ELP-stained elongated spermatids, even after 48 h of culture. B. As in A, but using the pre-immune serum as negative control. C and D are the brightfield images of the sections in A and B, respectively.