Example 9
Sensitive IgG ELISA after Transcytosis Assay
The entire procedure was performed at RT using an automated washer for the wash steps. A 384-well plate was coated with 30 μL/well of 1 μg/mL anti-human/mouse-IgG, Fcγ-specific in PBS for 2 hours followed by 1 hour incubation in blocking buffer PBS containing 1% BSA or 1 CroteinC for human and mouse IgG assays, respectively). Serially diluted samples from the transcytosis assay and standard concentrations of the antibody used in the transcytosis assay were added to the plate and incubated for 2 hours. After four washes, 30 μL/well of 50 ng/mL anti-human/mouse-F(ab)2-Biotin in blocking buffer was added and incubated for a further 2 hours. Following 6 washes, 30 μL/well of 50 ng/mL (huIgG assay) or 100 ng/mL (mIgG assay) Poly-HRP40-Streptavidin (Fitzgerald; in PBS containing 1% BSA and 0.05% Tween-20) was added and incubated for 30 min. After 4 washes, immune complexes were detected by addition of 30 μL/well of BM Chemiluminescence Substrate (Roche). The luminescence signal was measured using a luminescence plate reader and concentration calculated using the fitted standard curve. The sensitivity of the assay ranged from 10 pg/mL to 10 ng/mL.