The Eagle Biosciences TSH Ultrasensitive (Thyroid Stimulating Hormone) ELISA Assay Kit is a one-step enzyme immunoassay (sandwich). The HRP- conjugated antibody (signal) and the capture antibody coated on the plate react simultaneously with the TSH (Antigens) present in standards or samples. After an incubation of 1 hour, a specific sandwich complex (capture antibody-TSH-conjugated antibody) is resulting - immobilised on the surface of the wells. The unbound fraction will be removed by washing steps. The substrate solution is added into each well for colour development. The intensity of the colour in the well is proportional to the concentration of TSH in serum. Sample Types: serum. Range: 0.02 - 15 μIU/ml. Sensitivity: 0.007 μIU/ml. Time: 1.5 hours ? The Eagle Biosciences TSH Ultrasensitive ELISA Assay Kit is a Third generation enzyme immunoassay for the high sensitive determination of thyrotropin (TSH) in human serum. The Eagle Biosciences TSH Ultrasensitive ELISA Assay Kit is for research use only and not to be used in diagnostic procedures.