response to :sheath fluid

KUKURUGA@medmail.med.umich.edu
Mon, 27 Jan 1997 16:16:46 -0500 (EST)

I've used water as a sheath in a FACS440, and also in a FACScan. It had
no effect on immunofluorescence, although I noted a slight increase in
% c.v. for DNA histograms -- usually only a fraction of a percent.
Obviously, one cannot use water as sheath in a charge-based sorter
(I have used as little as 0.009% saline and still gotten reasonable
droplet charging, however).
One drawback might be that the possibility of back-flow into the sample,
thus changing osmolality and possibly affecting viable cells adversely,
assuming one runs cells viably.
I currently run an isotonic diluent from a commercial source ($13 / 20 liter),
-- I filter it on-site through a 0.2um cartridge before using -- in my Coulter
sorters and my XL. Haven't had a need to try water.
I suppost a good question might be . . . why do you want to use water?

MAK.

Mark A. KuKuruga
University of Michigan Flow Cytometry
kukuruga@medmail.med.umich.edu