Type A IgG antibodies recognize plasma-purified β2-GPI after treatment with glutaraldehyde. A hydrophobic ELISA plate was coated with plasma-purified β2-GPI (10 μg/mL), recombinant β2-GPI (10 μg/mL), and plasma-purified β2-GPI treated with glutaraldehyde (10 μg/mL). After blocking the plates, plasma of 2 patients with type A antibodies was added to the wells (1:100 dilution in blocking solution). The bound patient IgG antibodies were detected with an alkaline-phosphatase-labeled goat anti-human IgG antibody. PnPP was used as coloring substance. The obtained optical density was corrected for the optical density obtained with total IgG isolated from pooled plasma from 40 healthy volunteers (OD, 0.126). Error bars represent mean ± SEM of quadruple points.
