This human IL-10 ELISA kit employs the quantitative sandwich enzyme immunoassay technique to measure the levels of human IL-10 in the serum, plasma, or tissue homogenates. Antibody specific for IL-10 has been pre-coated onto the microplate. Standards and samples are pipetted into the wells and any IL-10 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated IL-10 antibody is added to the wells. After washing, avidin conjugated HRP is added to the wells, forming an antibody-antigen-enzyme-labeled antibody complex. Following a wash to remove any unbound HRP-avidin, the TMB substrate solution is added to the wells, and the color develops into blue. The color changes from blue to yellow after the addition of stop solution into the wells. The color intensity is in proportion to the amount of IL-10 bound in the initial step.