Optimized for use in bacterial cells, our BacLight™ series of bacterial viability and vitality assays for flow cytometry allow clear separation of living and dead cells based on various cellular characteristics. Due to the inherent differences between prokaryotic and eukaryotic cells, specialized dyes must be used to differentiate live and dead cell populations in bacteria.

  • Ease of use—Staining in 5–10 minutes with no wash steps.
  • Specific—Different colors for live and dead cells allows easy separation even in mixed populations.
  • Reliable—Consistent results regardless of bacterial species
  • Versitile—Also compatible with other detection platforms, including fluorescent microscopes, fluorometers and microplate readers

Membrane Integrity Viability Kit

The LIVE/DEAD™ BacLight Bacterial Viability Kit for flow cytometry is convenient and easy-to-use for monitoring the viability of bacterial populations as a function of the membrane integrity of the cell. Cells with a compromised membrane that are considered to be dead or dying will stain red, whereas cells with an intact membrane will stain green.

 
Figure 1. Micrococcus luteus and Bacillus cereus stained with the LIVE/DEAD BacLight Bacterial Viability Kit for flow cytometry. When incubated with the SYTO™ 9 and propidium iodide nucleic acid stains provided in this kit, live bacteria with intact cell membranes fluoresce green and dead bacteria with compromised membranes fluoresce red.

Citations

Product Laser Ex/Em* Live cell stain Dead cell stain Cat. No.
LIVE/DEAD BacLight Bacterial Viability Kit 488 nm 480/500 nm (L),
490/635 nm (D)
SYTO9 Propidium Iodide L7012
*Indicates excitation and emission. L = live, D = dead.

Metabolic activity viability kits

The BacLight™ RedoxSensor™ Bacterial Vitality Assay for flow cytometry provides effective reagents for evaluating bacterial cell health and vitality based on detecting activity of bacterial oxidases and reductases. Enhanced fluorescent signal is observed in bacterial cells with active metabolic processes. The BacLight RedoxSensor Bacterial Vitality kits also withstand fixation procedures.

 
Figure 2.
BacLight RedoxSensor Green Bacterial Vitality Kit. A mixture of healthy and killed Staphylococcus aureus cells were stained with 100 nM RedoxSensor Green reagent and propidium iodide. Dual-color flow cytometric analysis of the sample, gated on bacteria using scatter, shows both the healthy and the membrane-compromised cell populations. Similar results can be obtained with Escherichia coli.

Citations

Product Laser Ex/Em* Live cell stain Dead cell stain Cat. No.
BacLight RedoxSensor Green Bacteria Vitality Kit 488 nm 490/520 nm (L),
490/635 nm (D)
SYTO9 Propidium Iodide B34954
BacLight RedoxSensor CTC Vitality Kit 488 nm 480/500 nm (L),
490/635 nm (D)
SYTO24 Propidium Iodide B34956
*Indicates excitation and emission. L = live, D = dead.

Bacterial Membrane Potential Kit

The BacLight™ Bacterial Membrane Potential Kit for flow cytometry provides the fluorescent membrane-potential indicator dye, DiOC2(3), which exhibits green fluorescence in all bacterial cells, but it becomes more concentrated in healthy cells that are maintaining a membrane potential, causing the dye to self-associate and the fluorescence emission to shift to red. The red- and green-fluorescent bacterial populations are easily distinguished using a flow cytometer.

BacLight™ RedoxSensor™ Green Vitality Kit  
Figure 3. BacLight Bacterial Membrane Potential Kit for flow cytometry. The red vs. green fluorescence dot plot show Staphylococcus aureus incubated with 30 µM DiOC2(3) for 30 minutes in either the presence or absence of 5 µM carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Flow cytometer data were collected with log amplification.

Citations

Product Laser Ex/Em* Live cell stain Dead cell stain Cat. No.
BacLight Bacterial Membrane Potential Kit 488 nm 482/497 nm DiOC2(3) None B34950
*Indicates excitation and emission.