Dear list-members, I am looking for the original scans of the 8 Affymetrix micro-arrays that are part of the 2x2 factorial design example described by Robert Gentleman and Wolfgang Huber. I would like to use these in an exercise for a bachelor program bioinformatics. Converting raw tif-images into an expression matrix is part of the exercise. However, this is only possible when the original images and gene-id files are available. Off course, I contacted Robert Gentleman, but he never received those files. Please contact me if you have these files. Kind regards, Rene Nederhand "Sometimes I think the surest sign that intelligent life exists elsewhere is that none of it has tried to contact us." -Calvin & Hobbes (cartoon of Bill Watterson) R.J. Nederhand Project manager Bioinformatics Hogeschool Leiden _Post address:_ Postbus 382 2300 AJ Leiden The Netherlands _Visitors address:_ Zernikedreef 11 2333 CK Leiden The Netherlands

Hi Rene, sorry, I don't have the TIFF files either. Since you are going to use these data for teaching, I would just like to point out that this particular data set is not easy. The time factor has a drastic, transcriptome-wide effect on expression, which probably interferes with (or confounds) the normalization. While it is an interesting and biology-rich experiment, I am not sure it is the best as a textbook example for elementary microarray analysis. Needless to say that I/we were not aware of this complication when we prepared the exercise and it is on my list of things to do to revise it and use different set of arrays (but still a 2x2 factorial design). Bw Wolfgang ------------------------------------- Wolfgang Huber European Bioinformatics Institute European Molecular Biology Laboratory Cambridge CB10 1SD England Phone: +44 1223 494642 Fax: +44 1223 494486 Http: www.ebi.ac.uk/huber ------------------------------------- Rene Nederhand wrote: > Dear list-members, > > I am looking for the original scans of the 8 Affymetrix micro- arrays > that are part of the 2x2 factorial design example described by Robert > Gentleman and Wolfgang Huber. > > I would like to use these in an exercise for a bachelor program > bioinformatics. Converting raw tif-images into an expression matrix is > part of the exercise. However, this is only possible when the original > images and gene-id files are available. Off course, I contacted Robert > Gentleman, but he never received those files. > > Please contact me if you have these files. > > Kind regards, > > Rene Nederhand > > "Sometimes I think the surest sign that intelligent life exists > elsewhere is t