This assay employs the competitive inhibition enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with CLU. Standards or samples are added to the appropriate microtiter plate wells with Horseradish Peroxidase (HRP) conjugated antibody preparation specific for CLU. The competitive inhibition reaction is launched between with pre-coated CLU and CLU in samples. A substrate solution is added to the wells and the color develops in opposite to the amount of CLU