This kit is based on Double antibody-Sandwich ELISA detection method and takes 4h assay time. The microplate provided in this kit has been precoated with anti IFN-γ antibody. Add standard and properly diluted sample into relevant well respectively. After incubation, wash unbound components. Add biotinylated detection antibody. Then, it binds with IFN-γ bound to precoated antibody. Wash unbound components and add HRP-Streptavidin Conjugate (SABC). Wash unbound components again and add TMB substrate solution. Then, TMB was catalyzed by HRP to produce a blue color product that turned yellow after adding a stop solution. Read the O.D. absorbance at 450nm in a microplate reader. Calculate the concentration of IFN-γ in the sample by plotting standard curve. The concentration of the target substance is proportional to the OD450 value.