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Bruce H. Davis, M.D.
Dept. of Clinical Pathology
William Beaumont Hosp.
Royal Oak, MI 48073
810-551-5137
FAX 810-551-8057
On Thu, 8 Jun 1995, James Weaver 301-594-5879 FAX 301-594-3037 wrote:
> Uno Johansson posted:
>
> > Hi everybody!
> > Does anyone have experiences or references concerning mathematical handling
> > of data from surface activations markers on lymphocytes using FACS? Any
> > suggestions would be greatly appreciated. Thank you very much.
>
> An excellent place to start is:
>
> Flow cytometric titration of retroviral expression vectors: Comparison of
> methods for analysis of immunofluorescence histograms derived from cells
> expressing low antigen levels. Sladek, T.L. and Jacobberger, J.W. Cytometry 14
> 23-31 (1993).
>
> >From my limited evalution of CD69 as a proliferation marker (not published) I
> found the issue complex. From discussions I have had with others I am not alone
> in this response. In brief, If markers go from absent to bright such as CD25,
> then the evaluation can be done on % in the 'bright' area of the histogram. On
> the other hand, if the marker goes from dim to bright in a continuously changing
>
> fashion such as CD69 then the evaluation becomes difficult. This requires curve
> fitting that can handle asymmetric peaks such as a Weibull function. ModFit from
>
> verity has such a function but it does not recognise Log scale data. Since it
> was intended for DNA analysis, it assumes that all data is linear. If there are
> other analysis packages that will do Weibull fitting on Log scale data, I am not
>
> aware of them. If there has been further progress that I am not aware of I would
>
> be interested in hearing about it myself.This is a complex area and I wish you
> the best of luck.
>
>
>
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> James L. Weaver Email: WEAVER@FDACD.CDER.FDA.GOV
> Molecular Pharmacology Phone: 301-594-5879
> Division of Research & Testing FAX: 301-594-3037
> ORR, CDER, Food & Drug Admin. Voice: 'Hey you'
> Laurel, MD
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
>
>
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