Hi Jeppe To get from affyIDs' to genbank accession numbers: If there is a metadata package for your Affymetrix chip (you can get the metadata from the BioC website or using install.packages2()) Eg for package hgu133a library(hgu133a) Then use: hgu133aGENENAME() hgu133aACCNUM() Alternatively use annaffy() which is an excellent package library(annaffy) Then use either: aafGenBank(probesidlist, "hgu133a") aafSymbol(probesidlist, "hgu133a") If you've a custom chip, you may need to use AnnBuilder create the metadata yourself. Hope this helps Aedin Date: Thu, 3 Mar 2005 11:57:16 +0100 From: "JSPC (Jeppe Skytte Spicker)" <jspc@novonordisk.com> Subject: [BioC] AffyBatch: Replacing probe set IDs with Genebank Accesion numbers? To: <bioconductor@stat.math.ethz.ch> Message-ID: <ce4c1b6620e59840bb07f6f12256aedf026b618a@exdkba021.novo.dk> Content-Type: text/plain; charset="us-ascii" Hi All How do I get from the probe set IDs in the AffyBatch@exprs to e.g. Genebank acc. numbers? I would like to be able to make the replacement using the .GIN file because I am also looking at custom affy chips. Thank you in advance. Best regards Jeppe