①Measured by its binding ability in a functional ELISA. Immobilized SARS-CoV-2-S1-RBD at 5 μg/ml can bind human ACE2 , the EC50 is 196.4-272.1 ng/ml.
②Measured by its binding ability in a functional ELISA. Immobilized SARS-CoV-2-S1-RBD at 2 μg/ml can bind SARS-CoV-2-S Antibody , the EC50 is 7.481- 18.76 ng/ml.