Recombinant Biotinylated SARS-CoV-2 (COVID-19) S protein RBD, His, Avitag™ (MALS verified), 200µg

Background
It's been reported that SARS-CoV-2 can infect the human respiratory epithelial cells through interaction with the human ACE2 receptor. The spike protein is a large type I transmembrane protein containing two subunits, S1 and S2. S1 mainly contains a receptor binding domain (RBD), which is responsible for recognizing the cell surface receptor. S2 contains basic elements needed for the membrane fusion.The S protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity.

Source
Recombinant Biotinylated 2019-nCoV S protein RBD, His,Avitag (SPD-C82E9) is expressed from human 293 cells (HEK293). It contains AA Arg 319 - Phe 541 (Accession # QHD43416.1). Predicted N-terminus: Arg 319

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus, followed by an Avi tag.
The protein has a calculated MW of 28.2 kDa. The protein migrates as 33-36 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Endotoxin
Less than 1.0 EU per μg by the LAL method.

Purity
>95% as determined by SDS-PAGE.
>90% as determined by SEC-MALS.

Formulation
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4. Normally Mannitol or Trehalose are added as protectants before lyophilization.

Reconstitution
See Certificate of Analysis for reconstitution instructions and specific concentrations.

Bioactivity
Please refer to product data sheet.

Storage
Avoid repeated freeze-thaw cycles.
No activity loss was observed after storage at:
In lyophilized state for 1 year (4°C); After reconstitution under sterile conditions for 3 months (-70°C). 

References

(1) Wan Y, et al. J Virol. 2020. pii: JVI.00127-20.
(2) Benvenuto D, et al. J Med Virol. 2020.
(3) Chang CY, et al. AMB Express. 2020. 10(1):20.