KE00309 is a solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay (Sandwich ELISA). The TNFR1 (Soluble) ELISA kit is to be used to detect and quantify protein levels of endogenous TNFR1 (Soluble). The assay recognizes human TNFR1 (Soluble). An antibody specific for TNFR1 (Soluble) has been pre-coated onto the microwells. The TNFR1 (Soluble) protein in samples is captured by the coated antibody after incubation. Following extensive washing, another horseradish peroxidase (HRP)-TNFR1 (Soluble) protein. For signal development, followed by Tetramethyl-benzidine (TMB) reagent. Solution containing sulfuric acid is used to stop color development and the color intensity which is proportional to the quantity of bound protein is measurable at 450 nm with the correction wavelength set at 630 nm.