Figure 3. Motility assay in methylcellulose.

Mid-exponential phase cells were resuspended in 1% methylcellulose on glass slides and S-motility observed by time-lapse microscopy. Images show 7 cell tracks for (A) frzS mutant; (B) wildtype strain DZ2: and (C) pilT mutant over 9 min (Top). Images at 0, 3, 6, and 9 min are shown below. Cells were tracked in three independent experiments each with frzS, wildtype and pilT, but movement was only observed with frzS and wildtype DZ2. Scale bar is 5 µm.