Sample Type: Serum, plasma and other biological fluids. Intended Use: Sandwich ELISA, Double Antigen Sensitivity: <1.875ng/ml Range: 3.125-200ng/ml Specificity: Human Test Principle: This BioAssay? kit was based on sandwich enzyme-linked immune-sorbent assay technology. Thyroid peroxidase was pre-coated onto 96-well plates. And the Biotin-labeled Thyroid peroxidase was used as detection antigen. The standards, test samples and Biotin-labeled Thyroid peroxidase were added to the wells subsequently, and wash with wash buffer. HRP-Streptavidin Conjugate was added and unbound conjugates were washed away with wash buffer. TMB substrates were used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the anti-Thyroid peroxidase antibody amount of sample captured in plate. Read the O.D. absorbance at 450nm in a microplate reader, and then the concentrati