KE00333 is a solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay (Sandwich ELISA). The human GRP78/BIP ELISA kit is to be used to detect and quantify protein levels of endogenous human GRP78/BIP . The assay recognizes human GRP78/BIP. An antibody specific for human GRP78/BIP has been pre-coated onto the microwells. The human GRP78/BIP protein in samples is captured by the coated antibody after incubation. Following extensive washing, another antibody specific for human GRP78/BIP is added to detect the captured human GRP78/BIP protein. For signal development, horseradish peroxidase (HRP)-conjugated antibody is added, 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.