Kallikrein-related peptidase 3 (KLK3), which is also known as prostate-specific antigen, is an enzyme that is produced in the prostate gland in men and paraurethral glands in women. While KLK3 is present in small quantities in the serum of men with healthy prostates, it is elevated in patients with prostate cancer or other prostate disorders. Because of this, KLK3 can be used as a marker for prostate cancer screening as well as for post-treatment monitoring of patients with high-risk cases of the disease. Signosis’ Human KLK3 ELISA kit can accurately measure KLK3 levels in human samples and provides a human KLK3 protein standard for quantitative analysis.