The binding affinity of GALV RBD with MDTF cells expressing HA tagged PiT1, PiT2K522E or PiT2. GALV RBD tagged with both V5 and His was purified using high-performance nickel-NTA (Ni-NTA) agarose, serially diluted four times and applied to a binding assay for MDTFPiT1-HA (A) or MDTFPiT2K522E-HA and MDTFPiT2-HA cells (B). The kinetics of binding of GALV RBD was compared. The mean fluorescence intensity (MFI) for GALV RBD binding is indicated on the y-axis and GALVRBD concentration (mg) on the x-axis. Three independent experiments were performed and the mean ± standard deviation was presented in the curve.