– Nucleocapsid protein (N) is the major viral structural component; its main function is to protect and encapsidate the viral RNA forming viral RNP complex. It is encoded by the S segment vRNA and is abundantly expressed in the cytoplasm of infected cells. SARS-COV-2 Nucleocapsid Protein CTD Domain (His & Avi), Biotinylated is expressed in E. coli expression system with N-His-Avi tag. The predicted molecular weight is 17 kDa and the accession number is P0DTC9.