Phospholipid IgG / IgM ScreenELISA is a solid phase enzyme immunoassay for the separate quantitative detection of IgG and/or IgM antibodies against phospholipids in human serum. Each well is coated with highly purified bovine cardiolipin, ß2-glycoprotein I, phosphatidyl- serine, -inositol, ethanolamine, -choline and sphingomyelin. The assay is an aid in the diagnosis and risk estimation of thrombosis in patients with systemic lupus erythematosus and antiphospholipid syndrome (APS). Antibodies against phospholipids, components of the biological membranes, are specifi c for phospholipids such as cardiolipin, phosphatidyl -inositol, -ethanolamine, -choline,sphingomyelin and phosphatidic acid. Anti-phospholipid antibodies are frequently found in sera of patients with systemic lupus erythematosus (SLE) and related diseases. The occurrence of anti-phospholipid antibodies in patients with SLE and related diseases is typical for a secondary anti-phospholipid syndrome (APS). In contrast, antiphospholipid antibodies in patients with no other autoimmune diseases characterize the primary APS. Many studies have shown a correlation between these autoantibodies and an enhanced incidence of thrombosis, thrombocytopenia and habitual abortions (as a consequence of placental infarct). The exact mechanisms by which pathogenic anti-phospholipid antibodies induce thrombosis is not yet revealed fully.