Fig. 1

Expression and purification of rSARS-CoV-2-N protein. Recombinant plasmid containing the full length SARS-CoV-2 N gene was transformed into E. coli BL21 strain and induced with IPTG. E. coli cells were collected and dissolved in 10 mM PBS (PH 7.5) with 500 mM NaCl. After sonication, the E. coli cell lysate was centrifuged and the recombinant protein was purified from the supernatant by Talon™ IMAC affinity column. The E. coli cell lysate and the purified recombinant protein were analyzed using a 10% SDS-PAGE gel and stained with Coomassie brilliant blue staining. Lane 1: protein maker (Thermo Scientific); Lane 2: supernatant from sonicated E. coli cell lysate; Lane 3: pellet of sonicated E. coli cell lysate; Lane 4: purified recombinant protein