Bacterial Viability via Flow Cytometry

Using flow cytometry an investigator can determine what percentage of a prokaryotic population is alive and what percentage is dead. You can also distinguish other forms of viability via flow cytometry using a myriad of different viability stains. These can be seen with the corresponding paper under additional information on the bottom of the page. For the live/dead protocol the population is stained with two dyes, Syto-9 and PI. Syto-9 stains the DNA of cells indiscriminately, while PI stains only the cells with a compromised membrane. With the two stains combined, only live cells are stained with syto-9, with only compromised (dead) cells staining with PI.

 Bacterial Viability Results
 Bacterial Viability Results Table

For this example a 50/50 mix of live and dead cells were combined. The cells were stained with the Baclight kit and then run on the BD FACSCanto Flow Cytometer. Along the X-Axis is the Syto-9(FITC) parameter and the Y-Axis is PI(PE) parameter. We can see from the results how close the flow cytometer was at getting the correct reading. Below is another example using a 20% live/80% dead mixture.

 Bacterial Viability Results
 Bacterial Viability Results Table

From these examples we can see the utility of using flow cytometry to study bacterial viability. Please see the following for more information.

Additional Information: