Fig. 3

Applications of digital in-line holographic microscopy to track various unicellular microorganisms. a Trajectories of swimming Pseudomonas aeruginosa obtained by using DIHM (i, ii) and the corresponding statistical analysis of various swimming patterns, including meander, oscillation, helix, pseudohelix, and twisting patterns (iii, iv). Reprinted from ref. [158], Copyright 2014. b Various swimming patterns of Escherichia coli (E. coli) in near-surface and bulk regions. Trajectories of swimming E. coli (i, viii). Swimming patterns of E. coli in the bulk region: running and tumbling motions (ii) and slow random walk (iii). Swimming patterns of E. coli in the near-surface region: gyrating on a surface (iv), attaching and detaching motions (v), running and tumbling motions (vi), and swimming in circles (vii). Reprinted with permission from ref. [163], Copyright 2014, American Physical Society. c 3D trajectories of solitary and chain-forming Cochlodinium polykrikoides. Reprinted with permission from ref. [172], Copyright 2010, Springer-Verlag. d Trajectories of Prorocentrum minimum in helical motions (i-iii), obtained using DIHM. Probability density functions (PDFs) of helix parameters in the near and bulk regions: radius (R, iv) and pitch (P, v). Statistical differences in helix parameters between the near and bulk regions, represented as probability values (P-values): curvature (κ, vi) and torsion (τ, vii). Reprinted with permission from ref. [173], Copyright 2016, Springer-Verlag Berlin Heidelberg