Presentation
21 April 2017 Accurate live and dead bacterial cell enumeration using flow cytometry (Conference Presentation)
Fang Ou, Cushla McGoverin, Simon Swift, Frédérique Vanholsbeeck
Author Affiliations +
Abstract
Flow cytometry (FCM) is based on the detection of scattered light and fluorescence to identify cells with particular characteristics of interest. However most FCM cannot precisely control the flow through its interrogation point and hence the volume and concentration of the sample cannot be immediately obtained. The easiest, most reliable and inexpensive way of obtaining absolute counts with FCM is by using reference beads. We investigated a method of using FCM with reference beads to measure live and dead bacterial concentration over the range of 106 to 108 cells/mL and ratio varying from 0 to 100%. We believe we are the first to use this method for such a large cell concentration range while also establishing the effect of varying the live/dead bacteria ratios.

Escherichia coli solutions with differing ratios of live:dead cells were stained with fluorescent dyes SYTO 9 and propidium iodide (PI), which label live and dead cells, respectively. Samples were measured using a LSR II Flow Cytometer (BD Biosciences); using 488 nm excitation with 20 mW power. Both SYTO 9 and PI fluorescence were collected and threshold was set to side scatter. Traditional culture-based plate count was done in parallel to the FCM analysis. The concentration of live bacteria from FCM was compared to that obtained by plate counts. Preliminary results show that the concentration of live bacteria obtained by FCM and plate counts correlate well with each other and indicates this may be extended to a wider concentration range or for studying other cell characteristics.
Conference Presentation
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fang Ou, Cushla McGoverin, Simon Swift, and Frédérique Vanholsbeeck "Accurate live and dead bacterial cell enumeration using flow cytometry (Conference Presentation)", Proc. SPIE 10081, Frontiers in Biological Detection: From Nanosensors to Systems IX, 100810Q (21 April 2017); https://doi.org/10.1117/12.2251346
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CITATIONS
Cited by 1 scholarly publication.
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KEYWORDS
Bacteria

Flow cytometry

Luminescence

Biological detection systems

Light scattering

Current controlled current source

Nanosensors

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