title: Improved Tracking and Resolution of Bacteria in Holographic Microscopy Using Dye and Fluorescent Protein Labeling.
abstract: Digital holographic microscopy (DHM) is an emerging imaging technique that permits instantaneous capture of a relatively large sample volume. However, large volumes usually come at the expense of lower spatial resolution, and the technique has rarely been used with prokaryotic cells due to their small size and low contrast. In this paper we demonstrate the use of a Mach-Zehnder dual-beam instrument for imaging of labeled and unlabeled bacteria and microalgae. Spatial resolution of 0.3 μm is achieved, providing a sampling of several pixels across a typical prokaryotic cell. Both cellular motility and morphology are readily recorded. The use of dyes provides both amplitude and phase contrast improvement and is of use to identify cells in dense samples.
authors.affiliation: Graduate Aerospace Laboratories, California Institute of TechnologyPasadena, CA, USA; Department of Biomedical Engineering, McGill UniversityMontreal, QC, Canada.
authors.forename: Jay L
authors.initials: JL
authors.lastname: Nadeau
authors.affiliation: Graduate Aerospace Laboratories, California Institute of TechnologyPasadena, CA, USA; Department of Biomedical Engineering, McGill UniversityMontreal, QC, Canada.
authors.forename: Yong Bin
authors.initials: YB
authors.lastname: Cho
authors.affiliation: Graduate Aerospace Laboratories, California Institute of TechnologyPasadena, CA, USA; Institute for Astronomy, ETH ZürichZürich, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Kühn
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology Pasadena, CA, USA.
authors.forename: Kurt
authors.initials: K
authors.lastname: Liewer
keywords: Mach-Zehnder; bacterial motility; bacterial tracking; digital holographic microscopy; green fluorescent proteins; interferometric microscopy; quantitative phase imaging