Macrophage/Monocyte Chemotactic Protein-3 (MCP-3) plays an important role in the inflammatory response of blood monocytes, tissue macrophages, and eosinophils. MCP-3 is a chemotactic factor that attracts monocytes and eosinophils, but not neutrophils. It is also known to augments monocyte anti-tumor activity and induces the release of gelatinase B. BioVision’s MCP-3 (Human) ELISA Kit is based on the Sandwich-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with an antibody specific to Human MCP-3. Standards or samples are added to the micro ELISA plate wells that bind to the specific antibody. Then a biotinylated detection antibody specific for Human MCP-3 and Avidin-Horseradish Peroxidase (HRP) conjugate are added successively to each micro plate well and incubated. The wells are washed, a TMB substrate solution is added to the wells and blue color develops in proportion to the amount of MCP-3 bound. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm. The OD value is proportional to the concentration of Human MCP-3. The concentration of Human MCP-3 in the samples can be calculated by comparing the OD of the samples to the standard curve.