Lentivirus expresses the receptor-binding domain (RBD) of S1 protein in COVID-19 (SARS-CoV-2) coronavirus.

It has the human codon optimization for high expression in mammalian cells. It is expressed under a secretion leader. The secreted expressed S1-RBD (click to see its Amino Acid sequence) is about ~45 kDa, with a poly-histidine tag at the C-terminus (6-His tag) which allow to purify the S1-RBD Protein directly from the culture medium without need for cell lysis, via Ni NTA affinity column, .

The target was expressed under enhanced CMV promoter. A RFP-Blasticidin fusion dual selection marker under RSV promoter, allows to sort or select transduced cells via RFP fluorescent signal or via Blasticidin antibiotic. RFP signal provides a convenient, realtime monitoring the lentivirus performance.