FACS440 PMTs and related Question

Raymond B. Hester (rhester@jaguar1.usouthal.edu)
Fri, 20 Dec 1996 11:21:58 -0600 (CST)

Can someone tell me the expected lifetime of the PMTs installed with FACS
440s? The PMTs on our 440 are Thorn EMI model 4001-06-300 and we have had
them since the instrument was installed a little over eight years ago.
Only lately have we seen what appears to be a decrease in their
sensitivity as indicated by the peak channel that can be obtained with
green fluorescent polystyrene beads (Polyscience). We don't do a lot of two
color and when the PMT used to collect phycoerythrin is substituted for
the "green" PMT, and peak channels compared, the "orange" PMT gives an
approx. 3-fold higher peak channel with green beads. Does the "orange"
PMT have the same range with regard to wavelength sensitivity as the
green PMT so that we could swap them out if necessary when doing only one
color analysis?

Also, is there someone (in the U.S.) using a 440 and willing to analyze a
few samples that we would send you (beads, and maybe a couple of stained
and paraformaldehyde-fixed cell samples) so that we could compare our
results?

Since there are probably so few 440s out there and running on a daily basis,
the answer to the above could just be sent directly to me.

Thanks for any answers.

Ray

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Raymond B. Hester, Ph.D.
Flow Cytometry Lab
The University of South Alabama Each day is a gift;
Mobile, AL 36688-0002 that's why it's called,
Email: rhester@jaguar1.usouthal.edu "the present".
Voice: (334) 460-6029 - Anonymous
FAX: (334) 460-6073
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