For research use only. The TECHNOZYM® ADAMTS-13 Antigen ELISA is a chromogenic test for the determination of ADAMTS-13 antigen concentration in human plasma. ADAMTS-13 is the enzyme that cleaves vWF under laminar flow conditions. A functional defect of this enzyme leads to the presence of higher molecular weight forms of vWF and thus to increased platelet aggregation, mainly in the microvasculature. This is believed to be the major cause for thrombotic thrombocytopenic Purpura (TTP).