This monoclonal antibody provides sensitive, specific detection of human Epididymis Protein 4 (HE4), a clinically relevant biomarker associated with ovarian cancer, renal disease, and reproductive biology. Clone 12B3 delivers strong affinity and low background in ELISA, Western blotting, and antigen‑capture assays, enabling precise quantification of HE4 in serum, plasma, and purified protein samples. Its clean, reproducible signal supports oncology research, biomarker discovery, and development of HE4‑based diagnostic assays. MHE4‑80A‑12B3 offers consistent lot‑to‑lot performance, ensuring reliable detection across diverse analytical workflows