[BioC] affy vs rma

[Laurent Gautier]

On Mon, Jun 30, 2003 at 03:38:07PM -0700, Jingqin luo wrote:
> Hi, 
>   I want compare affy signal expression and rma, which
> are supposed to be somewhat hightly related or
> identical. But when I plot the normalized log2(affy)
> vs rma.There is a certain shape in all chips instead
> of being a ling. What might be the reasons?
>  Thanks!
> 

On Affymetrix chips, several probes are designed to hybridize
with each gene. The "expression value" represents a "summary
value" for the respective probe intensities. The Affymetrix
algorithm(s) and 'RMA' are different aprroaches to get
these "summary values"...




L.