Recombinant complex of three SARS-CoV-2 proteins NSP7 (nonstructural protein 7), NSP8 (nonstructural protein 8) and NSP12 (nonstructural protein 12). The NSP8_NSP7 construct contains an N-terminal His-tag (14xHis) followed by a TEV protease target sequence that allows cleavage of His-tag (TEV: tobacco etch virus cysteine protease BPS Bioscience #50308). The recombinant NSP12 construct is full length encompassing amino acids 1-932 (end). These recombinant proteins are co-expressed in an E. coli expression system and affinity purified.