Method Description

Purified beta-2 glycoprotein 1 (B2GPI) antigen is bound to the wells of a polystyrene microwell plate under conditions that preserve the antigen in its native state. Prediluted controls and diluted patient sera are added to separate wells, allowing any B2GPI IgG antibodies present to bind to the immobilized antigen. Unbound sample is washed away, and an enzyme-labeled antihuman IgG conjugate is added to each well. A second incubation allows the enzyme-labeled antihuman IgG to bind to any patient antibodies that have attached to the microwells. After washing away any unbound enzyme-labeled antihuman IgG, the remaining enzyme activity is measured by adding a chromogenic substrate and measuring the intensity of the color that develops. The assay can be evaluated spectrophotometrically by measuring and comparing the color intensity that develops in the patient wells with that of a 5-point calibration curve. The standard used to construct this curve is referenced to the reference calibrators for IgG beta-2-Glycoprotein I available from the Rheumatology Lab, Seton Hall University, St. Joseph's Hospital and Medical Center. Semiquantitative results are reported in standard IgG anti-B2GPI units (SGU).(Package Insert: QUANTA Lite beta 2 GP1 IgG ELISA. Inova Diagnostics; Revision 19, 07/2020)