Would the Human ACE2 (18-652) Recombinant Protein (mFc-Tag) #83986 or the Human ACE2 (multimeric) (18-652) Recombinant Protein #85054 work better in a competition assay?

Multimers are likely to demonstrate higher apparent affinity due to avidity effects. However, an exact recommendation for a competition assay would depend on other assay parameters, specifically assay format (in-tandem, classical sandwich, or premix), tags present on other proteins being used, and detection method.
If you want to immobilize ACE2, we recommend using the Human ACE2 (18-652) Recombinant Protein (mFc-Tag) #83986 due to the ease of immobilization by protein A or anti-Fc. 
If you want ACE2 in solution, we recommend using the Human ACE2 (multimeric) (18-652) Recombinant Protein #85054 if you are immobilizing other proteins by protein A or anti-Fc. This is because the multimeric protein does not cross-react at protein A or anti-Fc surfaces. If you would like ACE2 in solution but are not using protein A or anti-Fc surfaces for immobilization, either protein should work well. Finally, if you want the most potential avidity in solution, then the multimeric protein is preferable. 

Last updated: February 26, 2024