Hi, that is more a question of interest: Affymetrix provides the probe interrogation positions and they can be found in the corresponding "probe" package of each chip. But is this in respect to the currently used methods and aside from displaying/matching the probes at the correct chromosomal location only for the sake of completeness? Or is there in fact some analysis method (background correction, normalization, investigation etc.) which makes use of this information? regards, Benjamin -- Benjamin Otto Universitaetsklinikum Eppendorf Hamburg Institut fuer Klinische Chemie Martinistrasse 52 20246 Hamburg

Hi Benjamin, botto wrote: > Hi, > > that is more a question of interest: > > Affymetrix provides the probe interrogation positions and they can be > found in the corresponding "probe" package of each chip. But is this in > respect to the currently used methods and aside from displaying/matching > the probes at the correct chromosomal location only for the sake of > completeness? Or is there in fact some analysis method (background > correction, normalization, investigation etc.) which makes use of this > information? I don't know of any method that uses the chromosomal position in computing expression values. Best, Jim > > regards, > > Benjamin > > -- James W. MacDonald, M.S. Biostatistician Affymetrix and cDNA Microarray Core University of Michigan Cancer Center 1500 E. Medical Center Drive 7410 CCGC Ann Arbor MI 48109 734-647-5623 ********************************************************** Electronic Mail is not secure, may not be read every day, and should not be used for urgent or sensitive issues.