Hi, Is there any function which extracts raw intensities and probids from Affy Chips? I have 4 affy chips; 2 control and 2 experimental > getIntensityMatrix(exprs(affybatch)); > it gives different output......?? or should I do RMA which converts log base 2 values and then take antilog but..its still confusing..!! > do RMA(affybatch) > MatrixRMA <- exprs(myRMA); > MeanRawIntensities <- as.matrix(rowMeans(2^MatrixRMA[,1:2])); Can anyone guide me through this....? Thank you, Saurin