I am trying to compare gene expression changes between two gene expression data sets, one of which was generated on the Affymetrix MGU74v2 chip and the other of the later Affymetrix mouse chip MOE430. I am wondering if anybody has done a comprehensive comparison of these two chips at the sequence level and whether they are willing to share a table which summarizes this information. I understand that there is not a one to one mapping of probe sets between the two sets so understand that it would be quite large. Thanks Clive Glover Michael Smith Laboratories University of British Columbia 2185 East Mall Vancouver, BC V6T 1Z4

Clive, You can look at the Affymetrix array compariso spreadsheet for best matches between the two arrays. http://www.affymetrix.com/support/technical/comparison_spreadsheets.af fx -- Soumyaroop Bhattacharya, MS Analyst Pulmonary Medicine Brigham & Women's Hospital Harvard Medical School Thorn 908 75 Francis Street Boston MA 02115 Phone:(617)732-6265 Fax:(617)232-4623 sbhattacharya@rics.bwh.harvard.edu http://mysite.verizon.net/vzeo1xr3/