- Welcome to another
edition of Ask ExCyte.
I'm Tim Bushnell with Expert Cytometry,
and today's question comes from Nathan.
And Nathan asks, "What is sheath fluid?"
That's a great question.
Sheath fluid is the fluid that we run
to have our system actually work.
It's the fluid that flows
through our system that we will
inject our sample into.
On most flow cytometers out there,
we set the fluid flow rate
and we get this running in
laminar flow and then we inject
our sample into the center
of that flow at a slightly
different pressure.
Therefore, the cells stay
contained into a what we call a
core stream and spread out
along the velocity access to
generate the single cells that
we need passing by the laser
intercept.
Important things to remember
are the sheath fluid and the
sample tend not to mix.
So we don't have to use
PDS for our sheath fluid.
A lot of users I know, a
lot of core facilities, will
actually use just water.
We use water with a surfactant
in it, just to help keep
things lubricated.
It's also important to
remember anything that will
destabilize the laminar flow,
especially things you inject
into the sample or residuals
that are left in the tank after
washing,
things like detergents,
things like alcohols,
will destabilize that flow
rate and give you poor flow.
Once we establish that flow
rate and have that good
uniform flow, then flow
cytometry just rolls right along.
Thanks for another Ask ExCyte.
Until next time, be sure to
keep up with your flow cytometry
best practices right here
with your friends in Flow,
Tim and Team ExCyte.
