[BioC] Why "M" values?

[Richard Friedman]

Jenny,

	If I am not mistaken, "M" stands for "Minus" and in 
log2(Exp)-Log2(Control).
Similarly, "A" stands for "Add", as in 1/2[log2(Exp)+log2(control)].
The additional reference, is that "M" and "A" stand for "MicroArray".
I am not sure who came up with this. I think the Speed group,
but I am not sure who.

	Can anybodyelse help with this?

Best wishes,
Rich


On Sep 29, 2006, at 2:29 PM, Jenny Drnevich wrote:

> Hi all,
>
> Sorry to abuse the list with this general microarray question, but I 
> was
> hoping someone could quickly help me out with this... why are M-values
> (log2(ratio of expression in A to B)) called M-values?
>
> Thanks,
> Jenny
>
> Jenny Drnevich, Ph.D.
>
> Functional Genomics Bioinformatics Specialist
> W.M. Keck Center for Comparative and Functional Genomics
> Roy J. Carver Biotechnology Center
> University of Illinois, Urbana-Champaign
>
> 330 ERML
> 1201 W. Gregory Dr.
> Urbana, IL 61801
> USA
>
> ph: 217-244-7355
> fax: 217-265-5066
> e-mail: drnevich at uiuc.edu
>
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------------------------------------------------------------
Richard A. Friedman, PhD
Associate Research Scientist
Herbert Irving Comprehensive Cancer Center
Oncoinformatics Core
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"My novel has a hundred characters and it takes place over a year.
When I finish it, if it is shorter than Ulysses, then Joyce described 
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too much".
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