Gating strategy for determination of the binding efficiency of ACE2 variants with SARS-CoV-2 or SARS-CoV S1-Fc protein.

(A-B) Main cell population was identified and gated on Forward and Side Scatter. Single cells were further gated on FSC-A and FSC-H. The gated cells were plotted by FITC-A (zsGreen, as the ACE2 expressing population) and APC-A (S1-Fc bound population). The FITC-A positive cell population was plotted as a histogram to show the S1-Fc positive population as Fig 2B. The binding efficiency was defined as the percent of S1-Fc binding cells among the zsGreen positive cells. Shown are FACS plots representative of those that have been used for the calculations of binding efficiencies of ACE2 variants with S1-Fc. This experiment was independently repeated three times with similar results. (ZIP)