An enzyme linked immunosorbent assay (ELISA) for the quantitative determination of IgG and IgM antiphosphatidylserine antibodies (aPS) in individuals with systemic lupus erythematosus (SLE) and lupus-like disorders (antiphospholipid antibody syndrome).

Test principle

Samples, controls and calibrators are prediluted with buffer, which contains β₂ glycoprotein I as a cofactor, and incubated in micro wells, which have been coated with phosphatidylserine, allowing antiphosphatidylserine antibodies to bind. Unbound substances are removed by washing. An HRP conjugated detecting antibody, specific for human IgG or IgM, is added and binds to the phosphatidylserine/aPS antibody complex. After a washing step, added enzyme substrate reacts with the conjugate. The intensity of the resulting colour is proportional to the content of IgG or IgM antiphosphatidylserine antibodies in the sample.

Reagents and stability (after opening)

When stored at 2-8°C the reagents remain stable until the expiry date printed on the vials.