Extended Data Fig. 6 | Cell-surface staining with antibodies. a, Antibody
binding to the SARS-CoV-1 (blue) and SARS-CoV-2 (red) spike proteins
expressed on the cell surface. Expi293 cells were co-transfected with GFP and
full-length SARS-CoV-1 or SARS-CoV-2 spike genes. After 48 h, antibody binding
to spike protein in the GFP-positive cells was detected by f low cytometer.
The data show all antibodies tested were able to recognize the wildtype
SARS-CoV-2 spike protein but not SARS-CoV-1 spike protein. b, Monoclonal Ab
2-43 bound to S trimer expressed on Expi293 cell surface can be competed out
by mAbs directed against RBD but only minimally by mAbs to the NTD region.
Shown are representative data from three independent experiments.