KE00108 is a solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay (Sandwich ELISA). The GDF-15 ELISA kit is to be used to detect and quantify protein levels of endogenous GDF-15. The assay recognizes human GDF-15. An antibody specific for GDF-15 has been pre-coated onto the microwells. The GDF-15 protein in samples is captured by the coated antibody after incubation. Following extensive washing, another horseradish peroxidase (HRP)-conjugated antibody specific for GDF-15 is added to detect the captured GDF-15 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.