The biotin to protein ratio is 0.7 as determined by the HABA assay. Measured by its binding ability in a functional ELISA. When Recombinant Human ICOS Fc Chimera Protein is immobilized at 0.5 μg/mL (100 μL/well), Biotinylated Recombinant Human B7-H2 Fc Chimera Avi-tag that produces a 50% optimal binding response is found to be 1-6 ng/mL.