Coronaviruses are commonly comprised of four structural proteins: Spike protein (S), Envelope protein (E), Membrane protein (M) and Nucleocapsid protein (N) . The SARS-CoV-2 S protein is a glycoprotein that mediates membrane fusion and viral entry. The S protein is homotrimeric, with each ~180-kDa monomer consisting of two subunits, S1 and S2 . The RBD of SARS-CoV-2 binds a metallopeptidase, angiotensin-converting enzyme 2 (ACE-2). First detected in India in December 2020, the B.1.617.2, or Delta variant, is considered a Variant of Concern (VOC) .

The product should be stored at -25~-15℃ for 1 year.

1 month, 2 ~8 °C under sterile conditions after reconstitution.

3 months, -25~-15℃ °C under sterile conditions after reconstitution.

Recommend to aliquot the protein into smaller quantities when first used and avoid repeated freeze-thaw cycles.