This assay employs the competitive inhibition enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with Cross Linked C-Telopeptide Of Type I Collagen(CTXI) protein. Standards or samples are added to the appropriate microtiter plate wells then with a biotin-conjugated antibody specific to Cross Linked C-Telopeptide Of Type I Collagen(CTXI).