Figure 7.

Cell length and fluorescence in E. coli MG1655 MreB^sw-msfGFP cells are approximately maintained over several days

(A) Directly after fixation, cell length was similar to wild-type E. coli cells expressing cytoplasmic GFP (Figure 1B).

(B) MreB^sw-msfGFP fluorescence increased somewhat after fixation, by contrast to cytoplasmic GFP (Figures 2A, 2B, and 3A) but consistent with our microfluidic measurements (Figure 4).

(C) Cell length was approximately constant over several days in every fixative; there was a slight decrease in methanol during the first day but not nearly to the extent as wild-type cells (Figure 6A), suggesting that expression of MreB^sw-msfGFP affects cell mechanics.

(D) The small increase in MreB^sw-msfGFP fluorescence was accentuated after days of storage in all fixatives as long as cells were washed in PBS prior to fixation.

Measurements in (A,B) are averages of 2 experiments, and error bars represent 1 standard error of the mean, with n ≥ 144 cells each. Measurements in (C,D) are averages over cells, and error bars represent 1 standard error of the mean, with n ≥ 303 cells each.