title: Rapid, high-throughput tracking of bacterial motility in 3D via phase-contrast holographic video microscopy.
abstract: Tracking fast-swimming bacteria in three dimensions can be extremely challenging with current optical techniques and a microscopic approach that can rapidly acquire volumetric information is required. Here, we introduce phase-contrast holographic video microscopy as a solution for the simultaneous tracking of multiple fast moving cells in three dimensions. This technique uses interference patterns formed between the scattered and the incident field to infer the three-dimensional (3D) position and size of bacteria. Using this optical approach, motility dynamics of multiple bacteria in three dimensions, such as speed and turn angles, can be obtained within minutes. We demonstrated the feasibility of this method by effectively tracking multiple bacteria species, including Escherichia coli, Agrobacterium tumefaciens, and Pseudomonas aeruginosa. In addition, we combined our fast 3D imaging technique with a microfluidic device to present an example of a drug/chemical assay to study effects on bacterial motility.
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Fook Chiong
authors.initials: FC
authors.lastname: Cheong
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Chui Ching
authors.initials: CC
authors.lastname: Wong
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: YunFeng
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Mui Hoon
authors.initials: MH
authors.lastname: Nai
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Yidan
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore; School of Mechanical Engineering & Department of Global Biomedical Engineering, Sungkyunkwan University, Suwon, Korea.
authors.forename: Sungsu
authors.initials: S
authors.lastname: Park
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Department of Microbiology & Immunology, University of Illinois-Chicago, Chicago, Illinois.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Kenney
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore; Department of Mechanical Engineering, National University of Singapore, Singapore. Electronic address: ctlim@nus.edu.sg.
authors.forename: Chwee Teck
authors.initials: CT
authors.lastname: Lim
mesh_terms: D016960:Agrobacterium tumefaciens / Q000502:physiology; D018407:Bacterial Physiological Phenomena; D004926:Escherichia coli / Q000502:physiology; D006696:Holography / Q000379:methods*; D008858:Microscopy, Phase-Contrast / Q000379:methods; D018715:Microscopy, Video / Q000379:methods*; D009068:Movement; D011550:Pseudomonas aeruginosa / Q000502:physiology