Recombinant SARS-CoV-2, S1 Subunit Protein (RBD)

Recombinant SARS-CoV-2, S1 Subunit Protein (RBD) with C-terminal His tag, derived from the transfected human HEK293 cells.


Product Specifications

100 ug, 500 ug, or 1000 ug
Supplied as a 0.2 um filtered solution in PBS (pH 7.4)
His-tag affinity purification by immobilized metal ion affinity chromatography (IMAC)
Lot specific (see the label on the vial), determined by BCA protein assay
>90 %
Purity determined by:
SDS-PAGE under reducing conditions and visualized by Coomassie blue staining
Recommended Applications:
Lateral flow, indirect ELISA, sandwich ELISA, glycosylation analysis, binding assay, antibody generation, hybridoma screening, western blotting, biotin/dye/bead conjugation, binder selection, crystallization, and vaccine development.
Sandwich ELISA: this protein functions as a standard in conjunction with 130-10815 (capture antibody) and 130-10814 (detection antibody).
Standard curve


Accession Number:
  • QHD43416
Expressed Region:
Protein Name & Synonyms:
Spike protein, S Protein, S1 Subunit, Host Cell Receptor Binding Domain (RBD)


Expression System:
Human Embryonic Kidney 293 (HEK293) Cells
C-terminal his-tag
Molecular Weight (kDa):
Recombinant protein product has a calculated molecular mass of 25 kDa. Due to the abundant glycosylation, it migrates as approximately 30 kDa protein bands in SDS-PAGE under DTT, beta-mercaptoethanol reducing conditions. See deglycosylation analysis image below.
Figure 1. Deglycosylation of purified recombinant proteins. Purified proteins were untreated (Lane 2) or treated with Protein Deglycosylation Kit under native (Lane 3) or reducing (Lane 4) conditions. Deglycosylation treatment resulted in a mobility shift of the protein to produce one major band at the expected size, thus indicating that the untreated recombinant protein (Lane 2) was glycosylated.
Lane 1: Protein standard ladder (kDa)
Lane 2: Untreated protein under reducing conditions
Lane 3: Treated protein with deglycosylation enzymes under native conditions
Lane 4: Treated protein with deglycosylation enzymes under reducing conditions.
Binding Function
Binding Function
The product S1 RBD (Cat. 230-30162) was coated in 96 well plate and incubated with the serial diluted human ACE2 protein (Raybio, Cat. 230-30165). The bound ACE2 was detected by anti-ACE2 antibody using ELISA. The calculated EC50 is 4.23-9.26 ng/mL.

Stability & Storage

Ice packs
Upon arrival, the protein may be stored for 2 weeks at 4 °C. For long term storage, it is recommended to store at -20 °C or -80 °C in appropriate aliquots. Avoid repeated freeze-thaw cycles.

Related Coronavirus Proteins

Spike Protein, S1 Subunit, Host Cell RBD
Spike Protein, S2 Subunit
Nucleocapsid Protein
S1 Subunit Protein (RBD) with C-terminal Fc tag
S1 Subunit Protein (RBD) with C-terminal His-tag
S1 Subunit Protein with C-terminal His-tag
S2 Subunit Protein with C-terminal His-tag
Nucleocapsid Protein with C-terminal His-tag
We emploied this protein for site-specific glycosylation analysis. It works great.

University of California, Davis
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This product is furnished for LABORATORY RESEARCH USE ONLY.
Not for diagnostic or therapeutic use.