Used in biomedical research to quantify rat estriol (E3) levels in biological samples such as serum, plasma, or urine. This ELISA kit enables researchers to study hormonal changes during pregnancy, fetal development, and reproductive health in rat models. It is widely applied in endocrinology studies, toxicology assessments, and reproductive toxicity testing. The assay provides high sensitivity and specificity, allowing accurate measurement of estriol concentrations for monitoring estrogen metabolism and evaluating endocrine system function in experimental animals.