Abcam’s IL-12 Human in vitro ELISA (Enzyme-Linked Immunosorbent Assay) kit is designed for the quantitative measurement of IL-12 in Human serum, plasma, buffered solutions and supernatants. A monoclonal antibody specific for IL-12 has been coated onto the wells of the microtiter strips provided. Samples, including standards of known IL-12 concentrations, control specimens or unknowns are pipetted into these wells. During the first incubation, the standards or samples and a biotinylated monoclonal antibody specific for IL-12 are simultaneously incubated. After washing, the enzyme Streptavidin-HRP, that binds the biotinylated antibody is added, incubated and washed. A TMB substrate solution is added which acts on the bound enzyme to induce a colored reaction product. The intensity of this colored product is directly proportional to the concentration of IL-12 present in the samples.