REAGENT or RESOURCE	SOURCE	IDENTIFIER
Bacterial Strains
Escherichia coli (E. coli) strain DH5α	TIANGEN	Cat# CB101-02
Escherichia coli (E. coli) strain BL21 (DE3)	Novagen	Cat# 69450
MAX Efficiency DH10Bac Competent E. coli	Invitrogen	Cat# 10361-012
Chemicals, antibody and Recombinant proteins
PEI	Alfa	A04043896-1g
Anti-His/APC	Miltenyi Biotec	Cat# 130-119-820; RRID: AB_2751870
SARS-CoV-2 prototype RBD protein with his-tag, spike residues 319-541	This paper	accession number: EPI_ISL_402119
SARS-CoV-2 Alpha RBD protein with his-tag, spike residues 319-541	This paper	accession number: EPI_ISL_683466
SARS-CoV-2 Beta RBD protein with his-tag, spike residues 319-541	This paper	accession number: EPI_ISL_678615
SARS-CoV-2 Gamma RBD protein with his-tag, spike residues 319-541	This paper	accession number: EPI_ISL_833172
SARS-CoV-2 Delta RBD protein with his-tag, spike residues 319-541	This paper	accession number: EPI_ISL_6640916
SARS-CoV-2 Omicron RBD protein with his-tag, spike residues 319-541	This paper	accession number: EPI_ISL_410721
GD/1/2019 RBD protein with his-tag, spike residues 319-541	This paper	Accession number: EPI_ISL_410721
hACE2 protein, residues 18-615	This paper	accession number: NP_001358344
Critical Commercial Assays
HisTrap HP 5 mL column	GE Healthcare	Cat# 17524802
HiLoad 16/600 Superdex 200 pg	GE Healthcare	Cat# 28989335
Series S Sensor Chip CM5	GE Healthcare	Cat# 29149603
Membrane concentrator	Millipore	UFC901096
Deposited Data
Omicron RBD/hACE2 complex (Cryo-EM)	This paper	Protein Data Bank: 7WBL
Omicron RBD/hACE2 complex (crystal)	This paper	Protein Data Bank:7WBP
Delta RBD/hACE2 complex	This paper	Protein Data Bank: 7WBQ
Experimental Models: Cell Lines
HEK293T cells	ATCC	ATCC CRL-3216
BHK-21 cells	ATCC	ATCC CCL-10
Vero	ATCC	ATCC CCL-81
Recombinant DNA
pEGFP-N1	MiaoLingPlasmid	Cat# P0133
pEGFP-N1-hACE2	This paper	accession number: BAJ21180
pCAGGS	MiaoLingPlasmid	Cat# P0165
Software and Algorithms
PyMOL software	Molecular Graphics System, Version 1.8 Schrö dinger	https://pymol.org/2/
BIAcore® 8K Evaluation software	GE Healthcare	N/A
FlowJo V10	FLOWJO	https://www.flowjo.com/solutions/flowjo/downloads
Motioncor2	Zheng et al., 2017	N/A
COOT	Emsley and Cowtan, 2004	http://www.mrc-lmb.cam.ac.uk/personal/peemsley/coot/
Phenix	Adams et al., 2010	http://www.phenix-online.org/
MolProbity	Duke Biochemistry	http://molprobity.biochem.duke.edu/index.php