For In Vitro Research Use Only. The Technozym ADAMTS-13 ELISA is a test for the determination of ADAMTS-13 activity and 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.