Fig. 3

Competitive curve of cell capturing inhibition by RBD domain of Spike protein. 0.5 μg Spike S1 protein was coated on the microplate to capture the HEK293T/ACE2-GFP cells in presence of different concentrations of spike RBD protein. Amount of captured cells were determined by CCK8 test and expressed as relative value by setting the capability to capture cells of the non-RBD group as 100%. Data were plotted with a four-parameter logistic (4PL) regression curve fit of relative cell number (y-axis) versus the competitor concentration (x-axis)