KE00229 is a solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay (Sandwich ELISA). The IDO1 ELISA kit is to be used to detect and quantify protein levels of endogenous IDO1. The assay recognizes human IDO1. An antibody specific for IDO1 has been pre-coated onto the microwells. The IDO1 protein in samples is captured by the coated antibody after incubation. Following extensive washing, another antibody specific for human IDO1 is added to detect the captured human IDO1 protein. For signal development, 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.