FIG. 2.
Purification of soluble GN (GN-S) by nickel affinity chromatography. Culture supernatants were harvested at 72 h postinfection, purified, and dialyzed against PBS. The samples were analyzed by SDS-PAGE, one gel was stained with Coomassie brilliant blue (lanes 3 and 5), and another gel was analyzed by Western blotting (lanes 1, 2, and 4). Equal volumes were added to each well. Lane 1, six-His-tag molecular weight marker; lanes 2 and 3, cell culture medium added to column; and lanes 4 and 5, GN-S protein eluate from the 200 mM imidazole wash.