Kinetic binding assay using biolayer interferometry.

mAbs were purified on a Superdex200 Hi Load 16/600 column to remove aggregates. BLI analysis was performed on a Octet RED384 system using receptors (Acro Biosystems, FCM-H5286, FCM-C5284, and FCM-M82W5) or rPfCSP and PfCSP peptides loaded on HIS1K or SAX biosensors (ForteBio, 18-5122 and 18-5117) and probed into mAbs in a 2-fold dilution series. Assay conditions were individually optimized for each receptor-ligand pair. Data were fit using a 1:1 model on Octet Data Analysis Software version 12.0.2.3 (Molecular Devices LLC). Serial antibody concentrations used were 20, 10, 5, 2.5, and 1.25 μg/mL for pH 6.0 and 2000, 100, 50, 25, and 12.5 μg/mL for pH 7.4 for binding to the receptors, whereas antibody concentrations used for binding to rPfCSP were 2, 1, 0.5, 0.25, and 0.125 μg/mL.