FIG. 5.

Identification of ORF1b SARS-CoV replicase proteins by immunoblotting and immunofluorescence. (A) Lysates of SARS-CoV-infected (I) and mock-infected (M) cells were separated by SDS-PAGE, transferred to nitrocellulose, and probed with the anti-nsp12 (α-nsp12), -nsp13, -nsp14, -nsp15, or -nsp16 antibody. Additionally, preimmune (P) sera were used to probe blots. Mass markers are to the left of the blots, and observed masses of specific proteins are to the right of the blots. (B) Vero cells were infected with SARS-CoV or were mock infected for 12 h prior to fixation with methanol. Cells were labeled with the anti-nsp13 antibody and imaged as described in Materials and Methods. The second column is the image obtained at increased magnification to show detail of the fluorescence image.