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.
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.
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: