Purity and oligomer analyses of parallel purified coronavirus Spike antigens and antibodies.

A) SARS-CoV-2 Spike RBD, 1 mL HisTrap Excel purification. 10 μL of Load (L) (identical for each channel), flowthrough (F) and elution fractions (1–5) were analyzed by reducing, Coomassie-stained SDS-PAGE. B) mAbs (Anti SARS-CoV-2 Spike and anti Influenza Hemagglutinin) and pAb (healthy serum), 1 mL HiTrap Protein A purification. 10 μL of elution fractions (1–3) were analyzed by Coomassie-stained SDS-PAGE in the presence (+) and in the absence (-) of reducing agent. C-F) Coronavirus Spike antigens, 5 mL HisTrap Excel purification. Parallel purified Coronavirus spike antigens, desalted and concentrated offline, were analyzed by reducing SDS-PAGE (5 μg protein loaded) and analytical SEC-MALS. The calculated molecular weights of the major peak are shown in red.