Differential dynamic microscopy: a high-throughput method for characterizing the motility of microorganisms.
We present a fast, high-throughput method for characterizing the motility of microorganisms in three dimensions based on standard imaging microscopy. Instead of tracking individual cells, we analyze the spatiotemporal fluctuations of the intensity in the sample from time-lapse images and obtain the intermediate scattering function of the system. We demonstrate our method on two different types of microorganisms: the bacterium Escherichia coli (both smooth swimming and wild type) and the biflagellate alga Chlamydomonas reinhardtii. We validate the methodology using computer simulations and particle tracking. From the intermediate scattering function, we are able to extract the swimming speed distribution, fraction of motile cells, and diffusivity for E. coli, and the swimming speed distribution, and amplitude and frequency of the oscillatory dynamics for C. reinhardtii. In both cases, the motility parameters were averaged over ∼10(4) cells and obtained in a few minutes.
SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom. vincent.martinez@ed.ac.uk
Vincent A
VA
Martinez
Rut
R
Besseling
Ottavio A
OA
Croze
Julien
J
Tailleur
Mathias
M
Reufer
Jana
J
Schwarz-Linek
Laurence G
LG
Wilson
Martin A
MA
Bees
Wilson C K
WC
Poon
D058948:Cell Tracking / Q000379:methods*; D016825:Chlamydomonas reinhardtii / Q000502:physiology*; D004926:Escherichia coli / Q000502:physiology*; D008027:Light; D008124:Locomotion; D008853:Microscopy / Q000379:methods; D012542:Scattering, Radiation