KE00239 is a solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay (Sandwich ELISA). The Human CHI3L1/YKL40 ELISA kit is to be used to detect and quantify protein levels of endogenous human CHI3L1/YKL40. The assay recognizes human CHI3L1/YKL40. An antibody specific for human CHI3L1/YKL40 has been pre-coated onto the microwells. The human CHI3L1/YKL40 protein in samples is captured by the coated antibody after incubation. Following extensive washing, another antibody of biotinylated specific forhuman CHI3L1/YKL40 is added to detect the captured human CHI3L1/YKL40 protein. For signal development, Streptavidin-HRP 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.