Figure 5.

Detection of SARS-CoV-2 infection using our S-cell-based ELISA and comparison to protein-based ELISA kits. Serum samples (1:200 dilution) of 10 healthy controls (HC) and 21 patients (PT) were subjected to S-cell-based ELISA (A), an S1-protein-based ELISA kit (B), and an RBD-protein-based ELISA kit (C) to determine levels of anti-S antibodies. Pink bars represent the three samples from patients infected with the Alpha variant. Cell-based ELISA reads have been normalized to the read derived from individual serum interacting with wt-cells. Dotted line: cutoff value using the mean + 3SD of HC samples.