Fig. 1.

Characterization of the antibodies incorporated in the SARS-CoV-2 TRF-based S-assay. a Concomitant binding of anti-SARS-CoV-2 antibodies. The ability of the assay’s antibodies to bind simultaneously to SARS-CoV-2 was tested using the Octet Red biolayer interferometry (BLI) system. Biotinylated BL11 was immobilized to a streptavidin sensor and interacted with the spike’s S1 subunit. The complex was then immersed in a well containing the indicated antibody (pointed by an arrow), washed again (dashed vertical line), and immersed with the next antibody. b Schematic representation of the interaction of the assay’s antibodies with the spike protein. c Affinity of the anti RBD/NTD antibodies as determined by BLI analysis