Used for the quantitative determination of melatonin levels in biological samples such as serum, plasma, or tissue homogenates. This ELISA kit is widely applied in research settings to study circadian rhythm regulation, sleep disorders, and neuroendocrine function. It enables accurate measurement of melatonin concentrations, supporting investigations in neuroscience, endocrinology, and chronobiology. The kit is also utilized in preclinical studies to evaluate the effects of drugs, environmental factors, or lifestyle changes on melatonin secretion.