Hi, all, before starting any analysis on Affymetrix arrays is important to evaluate the arrays quality. How to evaluate the Affymetrix Genechips image artifacts is ok, ugly or bad but still reasnable using using the fitPLM of the affyPLM package? How to write the scripts? I am a new user, please give me more suggestions. Any help will be much appreciated. Best Regards Han Weinong hanweinong@yahoo.com __________________________________________________ [[alternative HTML version deleted]]