Browse by author
Lookup NU author(s): Simon Syvertsson, Dr Leendert Hamoen
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Within bacterial populations, genetically identical cells often behave differently. Single-cell measurement methods are required to observe this heterogeneity. Flow cytometry and fluorescence light microscopy are the primary methods to do this. However, flow cytometry requires reasonably strong fluorescence signals and is impractical when bacteria grow in cell chains. Therefore fluorescence light microscopy is often used to measure population heterogeneity in bacteria. Automatic microscopy image analysis programs typically use phase contrast images to identify cells. However, many bacteria divide by forming a cross-wall that is not detectable by phase contrast. We have developed 'ChainTracer', a method based on the ImageJ plugin ObjectJ. It can automatically identify individual cells stained by fluorescent membrane dyes, and measure fluorescence intensity, chain length, cell length, and cell diameter. As a complementary analysis method we developed 'NucTracer', which uses DAPI stained nucleoids as a proxy for single cells. The latter method is especially useful when dealing with crowded images. The methods were tested with Bacillus subtilis and Lactococcus lactis cells expressing a GFP-reporter. In conclusion, ChainTracer and NucTracer are useful single cell measurement methods when bacterial cells are difficult to distinguish with phase contrast.
Author(s): Syvertsson S, Vischer NOE, Gao YQ, Hamoen LW
Publication type: Article
Publication status: Published
Journal: PLoS One
Year: 2016
Volume: 11
Issue: 3
Online publication date: 23/03/2016
Acceptance date: 25/02/2016
Date deposited: 14/06/2016
ISSN (electronic): 1932-6203
Publisher: Public Library of Science
URL: http://dx.doi.org/10.1371/journal.pone.0151267
DOI: 10.1371/journal.pone.0151267
Altmetrics provided by Altmetric
