Device Description
INTENDED USE
For the detection and semi-quantitation of IgG anti-prothrombin (aPT) antibodies in individuals with systemic lupus erythematosus (SLE) and lupus-like disorders (e.g., antiphospholipid syndrome). For In Vitro Diagnostic Use.
SUMMARY OF THE TEST
Antiphospholipid antibodies are a heterogeneous group of immunoglobulins (IgG, IgM, IgA) that bind to several anionic phospholipids (e.g., cardiolipin, phosphatidylserine), to phospholipid-protein complexes, and to certain proteins in the absence of anionic phospholipids. The REAADS aPT ELISA test kit uses purified human prothrombin as antigen to detect IgG anti-prothrombin antibodies in human serum or citrated plasma in the absence of other exogenous cofactors or phospholipids. High serum or plasma levels of aPT antibodies may add valuable information in the laboratory assessment of antiphospholipid antibodies.
PRINCIPLE OF THE TEST
The test is an indirect ELISA. Diluted serum/citrated plasma samples, calibrators and controls are incubated in microwells coated with purified human prothrombin. After the removal of unbound proteins by washing, antibodies specific for human IgG labeled with horseradish peroxidase (HRP) are added forming complexes with the prothrombin bound antibodies. Following another washing step, the bound enzyme-antibody conjugate is assayed by the addition of a solution containing tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) as the chromogenic substrate. Color develops in the wells. Results are obtained by reading the O.D. of each test well in a spectrophotometer. Calibrator sera are provided with the IgG anti-prothrombin antibody concentration. The user will run a single point calibration, dividing the concentration value of the calibrator sera by the O.D. value of the calibrator providing a conversion factor. The O.D. values of the other samples are multiplied by the conversion factor to obtain IgG anti-prothrombin antibody concentrations in G units. Refer to Product Package Insert.