Not all antiphospholipid antibodies can be detecting by clotting test and require immunochemical ELISA tests. Testing is performed for anti-β2 glycoprotein I (anti-β2GPI) and the anticardiolipin (aCL).
The ELISA method uses a plate coated with either β2GPI
or phospholipid cardiolipin to which the patient serum is added, and then sandwiched with a secondary labelled antibody that allows quantitation of the bound antibodies. aCL.
IF a positive test is obtained, it is recommended that the assay be repeated after 12 weeks to eliminate any false positive results.