INTENDED USE The BIOS TSH ELISA Kit is a solid phase enzyme linked immunosorbent assay for the quantitative determination of the levels of Thyroid Stimulating Hormone (TSH) in human serum. TEST PRINCIPLE The BIOS TSH ELISA Kit is a solid phase enzyme linked immunosorbent assay based on the principle of antibody sandwich technique for the quantitative determination of TSH in human serum. The BIOS TSH ELISA Kit is composed of two key components: 1) Solid microwells pre-coated with monoclonal anti-TSH antibody, specific for the β . 2) Liquid conjugates composed of monoclonal anti-intact TSH antibody conjugated with horseradish peroxidase (HRP-anti-TSH conjugates).During the assay, the test specimen and HRP-anti-TSH conjugates, are incubated simultaneously with the coated microwells. The TSH, if present in the specimen, reacts to the anti- β TSH antibody coated on the microwell surface as well as the HRP-anti-TSH conjugates, forming an antibody sandwich immunocomplex. Unbound conjugates are then removed by washing. The presence of the conjugate complex is shown by development of a blue color upon additional incubation with substrate. The reaction is terminated with Stop Solution and the absorbance determined using a spectrophotometer at 450/620-690 nm.