Used in research settings to measure thyroid-stimulating hormone (TSH) levels in human serum or plasma. Enables assessment of thyroid function in clinical studies and helps investigate thyroid-related disorders such as hypothyroidism, hyperthyroidism, and autoimmune thyroid diseases. Commonly applied in endocrinology research, diagnostic development, and monitoring of therapeutic interventions. Provides a sensitive and specific method for quantifying TSH concentrations, supporting large-scale screening and longitudinal studies.