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.