title: Differential dynamic microscopy of bacterial motility.
abstract: We demonstrate a method for the fast, high-throughput characterization of the dynamics of active particles. Specifically, we measure the swimming speed distribution and motile cell fraction in Escherichia coli suspensions. By averaging over ∼10(4) cells, our method is highly accurate compared to conventional tracking, yielding a routine tool for motility characterization. We find that the diffusivity of nonmotile cells is enhanced in proportion to the concentration of motile cells.
authors.affiliation: SUPA and COSMIC, School of Physics & Astronomy, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: L G
authors.initials: LG
authors.lastname: Wilson
authors.forename: V A
authors.initials: VA
authors.lastname: Martinez
authors.forename: J
authors.initials: J
authors.lastname: Schwarz-Linek
authors.forename: J
authors.initials: J
authors.lastname: Tailleur
authors.forename: G
authors.initials: G
authors.lastname: Bryant
authors.forename: P N
authors.initials: PN
authors.lastname: Pusey
authors.forename: W C K
authors.initials: WC
authors.lastname: Poon
mesh_terms: D004926:Escherichia coli / Q000166:cytology* / Q000502:physiology*; D008027:Light; D008853:Microscopy / Q000379:methods*; D009068:Movement; D012542:Scattering, Radiation