Fig. 1

Analysis and purification of filamentous bacteria from a UPEC DNA-expression library by flow cytometry. Flow cytometry was carried out with the control populations of strains JW0941–1/pBAD24 (a) and JW0941–1/pLau80 (containing FtsZ-YFP, which induces strong filamentation) (b). The sorted populations of the UTI89 gDNA expression library in JW0941–1 are also shown: an initial high-speed, high-yield sort (c) and a subsequent lower speed “purity sort” to further enrich for filamentous cells (d). Dots represent single events plotted as side-scatter values of peak height and peak width, which correlates with filament length. Event density is colour coded with a heat-map of red (high density) to blue (displaying individual events). The gates for sorting are indicated with vertical lines, and the percentages of events contained within that gate are indicated. The “short” gate was determined to encompass greater than 99% of the control bacterial population (short cells), JW0941–1/pBAD24 (a)