BD Accuri News

Spotlight

Tim Bushnell, PhD
Discusses the BD Accuri C6 in the Core Lab

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Tim Bushnell is the director of Shared Research Labs at the University of Rochester Medical Center in New York, where he is responsible for the management and oversight of 14 research core and other laboratories. He formerly served as scientific and technical director of URMC's flow cytometry core facility. Dr. Bushnell spoke to us about the role of a personal flow cytometer in a core lab, and why he considers the BD Accuri™ C6 system a gateway to higher-end cytometry.

Read the full interview »

Noteworthy

Documentation for the BD Accuri C6 is available online. In addition to user guides and manuals, you will also find quick start guides for BD Accuri™ C6 software and the BD CSampler™ accessory.

Visit the BD Accuri resources page »

Application Highlight

Microbiology on the BD Accuri™ C6

Flow cytometry can provide accurate, reliable, multiparametric data on microorganisms, including bacteria and yeast. Light scatter data can reveal basic information about microbes' size, shape, and surface features, while fluorescent stains can assess their cell viability, metabolic activity, and concentration. In some cases, this information might be enough to identify specific microorganisms in a heterogeneous sample; in others, additional techniques such as PNA-FISH can be added.

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Live/dead discrimination of E. coli using the BD Cell Viability Kit
 
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Live/dead discrimination of E. coli using the BD Cell Viability Kit
E. coli cells were grown in LB broth overnight and treated with Conflikt® Detergent Disinfectant (1%) at room temperature for 5 minutes to induce cell death. The treated and untreated samples were stained with the BD Cell Viability Kit (Cat. No. 349483) and acquired on a BD Accuri C6 for 30 seconds on the Fast flow rate (66 µL/min) with SSC-H threshold = 10,000 to exclude debris. Results: A. Cells were initially gated on an FL2-A vs SSC-A plot as described in the product insert sheet. B, C. Simultaneous TO and PI staining allows distinction among live (TO+PI), dead (TO+PI+), and injured (TO+PIint) cell populations, revealing increased cell injury and death in the treated sample as expected. The TOPI+ population was excluded from the analysis as debris.

Conflikt is a registered trademark of Decon Labs, Inc

The BD™ Cell Viability Kit provides a simple, two-color method to monitor microbial cell viability on the BD Accuri C6 flow cytometer. Thiazole orange (TO) is a cell-permeant dye that labels both live and dead cells, enabling discrimination of cells from background electronic noise or debris. Propidium iodide (PI) is impermeable to healthy cells with intact membranes, but permeates cells with compromised membranes such as dead cells. When used in combination, as described in a new product information sheet, these dyes provide a rapid, simple method to distinguish live, dead, and injured bacteria, yeast, or eukaryotic cells.


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Detection of GFP expression in bacteria
 
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Detection of GFP expression in bacteria
Samples containing wild-type (left column) or GFP-transfected (middle column) E. coli B, or a mixture of the two (right column), were acquired on a BD Accuri C6. A. FSC vs SSC scatter plots were used to gate cells and exclude debris. B. FL1 histograms were used to identify transfected (peak about 103.5) and non-transfected (peak about 101) populations. Transfected and non-transfected populations were resolved clearly in the mixed population. Data courtesy of Tim F. Cooper, Dept. of Biology and Biological Chemistry, University of Houston, Houston, TX, USA.

Microorganisms can be transfected with fluorescent reporter proteins to study gene and protein expression. With over six decades of dynamic range, the BD Accuri C6 can detect bright signals from Green Fluorescent Protein (GFP) and other fluorescent proteins, all on the same scale, using the standard optical filter configuration. Optional filters can further increase signal resolution and the variety of fluorescent probes used.

Flow cytometry's ability to characterize microorganisms makes it a powerful and effective methodology in industrial bioprocessing. A recent white paper bioprocess monitoring website, describe how researchers and engineers are using the BD Accuri C6 to monitor microbial fermentation, control bioreactors in real time, and evolve desired microbial strains.


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Analysis of phytoplankton in water samples from Saginaw Bay
 
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Analysis of phytoplankton in water samples from Saginaw Bay
Water samples were taken from multiple sites in Saginaw Bay, MI, in June 2009 and analyzed on the BD Accuri C6. A. Plots of phycocyanin fluorescence (FL4, x-axis) versus chlorophyll fluorescence (FL3, y-axis) were used to separate fluorescent phytoplankton into cyanobacteria (region P6) and other fluorescent phytoplankton (P7). B. The non-cyanin expressing phytoplankton (P7) were further analyzed and enumerated according to the presence (P8) or absence (P9) of PE signal (y-axis). Microorganism counts (not shown) showed that Sites 1 and 2, closest to the mouth of the Saginaw River, had the most cyanobacteria, resulting in the largest blue-green and green algal blooms later in the season. Site 23, the closest to open water, had the lowest counts for all species. Data courtesy of Juli Dyble Bressie, PhD, NOAA, Seattle, WA, USA.

Many aquatic microorganisms are distinguished by naturally occurring fluorophores such as chlorophyll (found in all phytoplankton) and phycobilins (found in cyanobacteria), which have characteristic optical wavelength excitation and emission profiles. Another recent white paper and webinar, available at our marine research website, explain how these fluorophores can be exploited in aquatic microbiologic research. They allow researchers to use flow cytometry to directly detect, discriminate, analyze morphology, and quantify these organisms using fluorescence-detection methods, without the addition of extraneous dyes or probes.

View more sample microbiology data on the BD Accuri C6 »

Tips & Tricks

Decontaminate

This month, BD Technical Support representatives share two tips for preventing contamination in the Sample Injection Probe (SIP), flow cell, and sheath fluid bottle of the BD Accuri C6.

After each experiment, prepare a tube of decontamination solution, diluted to working concentration according to the package instructions. Run for 2 minutes on Fast speed. Follow by running filtered, deionized water for 2 minutes on Fast speed to flush out cellular debris and prevent clogging. BD Accuri™ Decontamination Solution (Cat. No. 653154 or 653155) is designed for this purpose.

If sheath fluid remains in the fluidics bottle for more than two days, to prevent bacterial contamination, add BD Accuri™ Bacteriostatic Concentrate Solution (Cat. No. 653156).