Fig. 8.

Localization of ALDH1A enzymes in the human testis. ALDH1A1, ALDH1A2, and ALDH1A3 have distinct localization patterns in the human testis. Each panel is representative of immunohistochemical results from three different human testes. All were fixed in Bouin’s fluid and embedded in paraffin. Brown stain indicates immunopositive reaction for ALDH1A1 (A), ALDH1A2 (B–D), and ALDH1A3 (E). A negative control (F) used rabbit IgG instead of primary rabbit antibody. The original magnification was 225× for each. The bar at lower left of each panel represents 10 microns. Cell types are indicated by arrows as follows: blue, Sertoli cells; yellow, spermatogonia; red, primary spermatocytes; green, round spermatids; black, peritubular cells; gray, interstitial cells.