Used in clinical diagnostics to detect and quantify alpha-fetoprotein levels in human serum or plasma. Commonly applied in prenatal screening to assess the risk of neural tube defects and other fetal abnormalities. Also utilized in the diagnosis and monitoring of liver diseases, including hepatocellular carcinoma and certain germ cell tumors. Provides a sensitive and specific measurement for tumor marker evaluation during cancer treatment and follow-up. Widely used in research settings for studying liver function and fetal development.