Figure 6

Immunohistochemical localization of SPAM1 in the human epididymis using multiphoton confocal microscopy. The magnification of tissue sections is the same as is shown in A. Images are taken in the red confocal channel to help eliminate the effect of autofluorescence which occurred in varying degrees depending on the laboratory in which the slides were fixed before sectioning. Preimmune serum was used for negative controls (A, D, and F). The epithelium (E) in A which is from the human proximal corpus (Subject #4) appears red, while SPAM1 is indicated by the yellow-green color in the epithelial lining of the test sections, B and C, also from the corpus of the same male. In C the nuclei are stained with propidium iodide to enhance the visualization of the FITC green color of the signal. Note that the green color in the elastic fibers in the stroma underlying the epithelium in test and control is due to strong autofluorescence and not the primary antibody. D and E, and F and G are from Subject #5, these slides as well as those from the macaques had very high levels of autofluorescence, however the sperm in the lumen (L) serve as a positive control, varying in staining intensity between F and G. Although no sperm are present in the caput test section, the epithelial lining for control (D) and test (E) are quite different in color.