Fig 1. Schematic of the study.

(A) Six E. coli clones were isolated from growth on LB agar. Each was used to inoculate six sealed tubes of 5 mL liquid LB. The resulting populations were maintained in starvation for 0, 1, 3, 6, 15 or 30 days. Populations were then analysed by growing colonies from single cells in drops of 100 nL fresh LB medium. Individual drops were collected in microplate wells for further analysis with complementary methods. (B) Millifluidic droplet analyser principles. Droplets are prepared in a cross junction (see S1 Movie) and stored in a PTFE tube (500μm inner diameter). By controlling the pressure at each side the sequence of drops can be moved back and forth in front of the measurement point (see S2 Movie).