BD TSO Problem Fixed

Jim Houston (jim.houston@stjude.org)
Tue, 03 Sep 1996 16:40 -0500 (CDT)

The message that I gave awhile back concerning instability problems with
a BD FacsVantage equipped with a TSO has been solved. A major culprit was
a heat stability problem contained in the system power supply cage
located under the main card cage. The problem is fixed by mounting a fan
to the outside of the cage blowing air in and also by leaving the access
door open. The problem was apparent in the original and a substitute power
supply. BD is aware of the problem and is working on a more permanent fix.

Other site specific modifications were done to enhance the TSO's daily
monitoring and setup.

For the first time in 9 months the system can be turned on, the same DDF
used, same System pressure etc and obtain the same Drop Delay as the past
few days. I can now obtain purities >99% at rates of 10k/sec plus. Sort
streams are visable from 5 feet away (tight streams).

A test sort last Friday using a ficolled Bone Marrow sample of about 15
million cells was stained with CD3-Fitc, CD34-PE, CD45-PCP. CD3+CD45+
and CD34+CD45+ cells were sorted into seperate tubes. The sample was
sorted at a rate >10k/sec. The initial CD34 % was 1.3 and the CD3 was 7.7.
The sorted CD3 were >98% pure. The CD34 sorted cells were >95%. The
recovery was about 52%. These results were better than expected with the
problems I had been experiencing with this system most of this year.

The problem is fixed. I just need to tweak it.

I would like to hear from anyone else with a TSO or who is going to
purchase one.

Thanks to BD , Alfonso discovered the heat problem and John Cardot and
Larry Duckett modified the system to meet my particular needs.