Table 2.

Components of ACE2 activity standard curve solution (per well)^a

rACE2 standard	Diluted rACE2 conc. (ng/ml)	rACE2 volume/well (μl)	ACE2 inhibitorb or ddH2O volume/well (μl)c	ACE2 substrate/assay buffer (μl)	Total volume/well (μl)	Final rACE2 conc. (ng/ml)
1	333.33	15	10	75	100	50
2	166.66	15	10	75	100	25
3	83.33	15	10	75	100	12.5
4	41.67	15	10	75	100	6.25
5	20.83	15	10	75	100	3.13
6	10.42	15	10	75	100	1.56
7	0	15d	10	75	100	0

rACE2 recombinant ACE2, ddH ₂ O double-distilled H₂O, Conc concentration

^aThe volume of each component listed is for each well, to give a total volume of 100 μl of ACE2 enzymatic reaction solution, on a 96-well microplate. Each reaction is performed in duplicate

^bACE2 inhibitor: MLN-4760 or DX600

^cFor each dilution, one duplicate reaction is performed in ddH₂O (10 μl), and another duplicate is performed with the addition of ACE2 inhibitor MLN-4760 or DX600 (10 μl, from stock of 10⁻⁵ M)

^dStandard #7 is a blank, with the addition of assay buffer alone, instead of rACE2