KE20010 is a solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay (Sandwich ELISA). The TGF-beta1 ELISA kit is to be used to detect and quantify protein levels of endogenous TGF-beta1. The assay recognizes Rat TGF-beta1. An antibody specific for TGF-beta1 has been pre-coated onto the microwells. The TGF-beta1 protein in samples is captured by the coated antibody after incubation. Following extensive washing, another antibody of biotinylated specific for TGF-beta1 is added to detect the captured TGF-beta1 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. This ELISA kit is cross-reactive with bovine, porcine, equine, and caprine. Therefore, the culture medium should not contain serum components associated with the above species.