REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Goat anti-human IgG (H+L)/HRP	JACKSON	Cat #109-035-088; RRID: AB_2337584
Anti-His/HRP	ThermoFisher	Cat # MA1-21315; RRID: AB_557403
Bacterial and Virus Strains
SARS-COV-2 VSV pseudotyped virus	NIFDC (Nie et al., 2020)	N/A
Authentic SARS-CoV-2 virus (2019-nCoVBetaCoV/Wuhan/AMMS01/2020)	Qin’s lab	N/A
Biological Samples
PBMCs from COVID-19 convalescent patients	Youan hospital	N/A
Chemicals, Peptides, and Recombinant Proteins
Ficoll-Paque Plus	GE Healthcare	Cat #17144002
Fetal bovine serum (FBS)	ThermoFisher	Cat #10099
RPMI 1640 medium	ThermoFisher	Cat #12633012
SARS-COV-2 spike protein, His-tag	Sino Biology	Cat # 40589-V08B1
SARS-COV-2 RBD protein, His-tag	Sino Biology	Cat # 40592-V08B
Biotinylated SARS-COV-2 spike protein	Sino Biology	Cat # 40589-V08B-B
Biotinylated SARS-COV-2 RBD protein	Sino Biology	Cat # 40592-V08B-B
0.4% (w/v) Trypan blue stain	ThermoFisher	Cat # 15250061
Streptavidin M-280 Dynabeads	ThermoFisher	Cat # 60210
1x PBS, pH 7.4	ThermoFisher	Cat # 10010031
EDTA 0.5M, pH8.0, RNase-free	ThermoFisher	Cat # AM9260G
TMB Chromogen Solution (for ELISA)	ThermoFisher	Cat # 002023
NaCl (5 M), RNase-free	ThermoFisher	Cat # AM9760G
Surfactant P20	GE Healthcare	Cat #BR100054
ACE2 Protein, Human, Recombinant (His Tag)	Sino Biology	Cat # 10108-H08B
HG1K IgG1 antibody against H7N9	Sino Biology	Cat #HG1K
DMEM	ThermoFisher	Cat #11965092
HEPES (1 M)	ThermoFisher	Cat #15630080
LMP agarose	Promega	Cat #V3841
Crystal violet	SigmaAldrich	Cat # C0775
Formaldehyde solution	SigmaAldrich	Cat # F8775
Polyethylenimine	Polysciences	Cat # 23966-2
Papain	Sangon Biotech	Cat # A501612-0025
Iodoacetamide	SigmaAldrich	Cat # I1149
Critical Commercial Reagents
EasySep Human B Cell Enrichment Kit	STEMCELL	Cat #19054
EasySep Human Memory B Cell Isolation Kit	STEMCELL	Cat #17864
Chromium Single Cell 5′ Library Construction Kit	10X Genomics	Cat #1000020
Chromium i7 Multiplex Kit	10X Genomics	Cat #120262
Chromium Single Cell V(D)J Enrichment Kit, Human B Cell	10X Genomics	Cat #1000016
Chromium Single Cell 5′ Library & Gel Bead Kit	10X Genomics	Cat #1000014
Chromium Single Cell A Chip Kit	10X Genomics	Cat #1000009
SA sensor chip	GE Healthcare	Cat #29104992
Spike Protein ELISA kit	Sino Biology	Cat #KIT40591
Ni Sepharose 6 Fast Flow	GE healthcare	Cat # 17531803
Superose 6 Increase 10/300 GL	GE healthcare	Cat # 29091596
RNeasy Mini Kit	QIAGEN	Cat # 74104
PrimerScript RT Reagent Kit	TaKaRa	Cat # RR037B
PowerUp SYBR Green Master Mix Kit	Applied Biosystems	Cat # A25741
Deposited Data
Cryo-EM structure of SARS-COV-2 spike and BD23-Fab	This paper	PDB: 7BYR
Electron microscopy density map of SARS-COV-2 spike and BD23-Fab	This paper	EMDB: EMD-30247
Antibody amino acid sequences	This paper	European Genome-Phenome Archive: EGAS00001004412
Experimental Models: Cell Lines
HEK293F cells	ThermoFisher	Cat # 11625019
Huh7 cells	NIFDC (Nie et al., 2020)	N/A
Vero E6 cells	Qin’s lab	N/A
Experimental Models: Cell Lines
hACE2 transgenic mice	Qin’s lab	N/A
Oligonucleotides
5′-TCGTTTCGGAAGAGACAGGT-3′	Qin’s lab	N/A
5′-GCGCAGTAAGGATGGCTAGT-3′	Qin’s lab	N/A
Recombinant DNA
SARS-CoV-2 S gene, residues 1-1208, pcDNA	Sino Biology	N/A
SARS-CoV-2 S gene, residues 1-1208, 2P and furin cleavage mutation, T4 fibritin trimerization motif, 8xHisTag, pcDNA	This paper	N/A
Software and Algorithms
cutadapt (2.9)	Martin, 2011	https://cutadapt.readthedocs.io/en/stable/installation.html
CellRanger (3.1.0)	10x Genomics	https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/latest/installation
SingleR (1.0.5)	Aran et al., 2019	https://bioconductor.org/packages/release/bioc/html/SingleR.html
Seurat (3.1.3)	Satija et al., 2015	https://satijalab.org/seurat/install.html
IgBlast-1.15.0	National Center for Biotechnology Information (NCBI)	ftp://ftp.ncbi.nih.gov/blast/executables/igblast/release/1.15.0/
igraph (1.2.5)	Csardi and Nepusz, 2006	https://cran.r-project.org/web/packages/igraph/index.html
SAAB+	Kovaltsuk et al., 2020	https://github.com/oxpig/saab_plus
SerialEM software	Mastronarde, 2005	https://bio3d.colorado.edu/SerialEM
MotionCor2	Zheng et al., 2017	https://emcore.ucsf.edu/ucsf-motioncor2
Gctf program (v1.06)	Zhang, 2016	https://www.mrc-lmb.cam.ac.uk/kzhang/Gctf
RELION (v3.07)	Zivanov et al., 2018	https://www2.mrc-lmb.cam.ac.uk/relion
ResMap	Kucukelbir et al., 2014	http://resmap.sourceforge.net
UCSF Chimera	Pettersen et al., 2004	https://www.cgl.ucsf.edu/chimera
PHENIX	Adams et al., 2010	https://www.phenix-online.org
Coot	Emsley et al., 2010	https://www2.mrc-lmb.cam.ac.uk/Personal/pemsley/coot
Pymol	Schrödinger	https://pymol.org/2/