Pro-Relaxin-3 in Mouse Testis. Pro-Relaxin-3 was detected in immersion fixed frozen sections of adult mouse testis using Goat Anti-Human Pro-Relaxin-3 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3107) at 15 µg/mL overnight at 4 °C. Tissue was stained using the Anti-Goat HRP-DAB Cell & Tissue Staining Kit (brown; Catalog # CTS008 ) and counterstained with hematoxylin (blue). Specific staining was localized to spermatocytes. View our protocol for Chromogenic IHC Staining of Frozen Tissue Sections .