Hi All, I have done a very simple cDNA microarray experiment (Wild type -Cy5 Vs Mutant variety-Cy3 and color flip expriment on our mouse arrays). This experiment was repeated and i have results of all these four experiment. Using Marray norm i could normalise the data and have expoted M and A values on excel sheet. However, I need your suggestions to interpret the result using R package (Genes which are differentialyy expressed in mutant type compared to the wild type). I wanted to use multtest package but have not been able to get anything out from it yet. Binita Dr. Binita Dutta MicroArray Facility(MAF) UZ Gasthuisberg Onderwijs en Navorsing Herestraat 49 3000 Leuven Belgium