 |
 |
 |
 |
> 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
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
|
|