FW: BAL and clogging

Calman Prussin (CPRUSSIN@atlas.niaid.nih.gov)
Tue, 2 Jul 1996 22:55:57 -0400

>I have been doing flow on BAL (bronchoalveolar lavage) and have
>recently graduated up to the FACS Vantage with nice results. A problem
>that seems to nag at us is that the Vantage, having a stream in air
>setup, has only a 70 micron aperture and is subject to clogging even
>though we filter it through 50 micron nylon mesh.
>
>Normally, with PBMC one can see the changes in scatter when clogs occur
>and then clear out the clog. With BAL however, the scatter-gram is not
>nearly as distinct, and as such, cloggs are more difficult to detect
>(using either linear or log SSC, with linear FSC). Since each BAL
>sample is quite precious, I can ill afford to lose a sample due to such
>clogging.
>
>My proposed solution is to spike each sample with non-fluorescent beads
>of say 2-3 microns in diameter. My hope is that they show up as a sharp
>peak just to the left of the lymphs. Movement of that peak would be
>more obvious and would alert the operator that there was trouble.
>
>Questions for the group:
>1.) Is this overkill?
>2.) Are there other simpler or better ways to do this?
>3.) Will it work at described above? What size beads should I use?

_______________________
Calman Prussin
Laboratory of Allergic Diseases
NIAID/ National Institutes of Health
calman@nih.gov

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