Dear all I have been trying to read CEL files from the E.coli antisense genome array made by affymetrix and realised that the cdf file is not available in bioconductor. On the http://www.bioconductor.org/data/cdfenvs/cdfenvs.html site, there are a number of CDF files for E.coli that can be downloaded. The problem is that there is no such file for the E.coli antisense chip but there are cdf files for the "ecoliasv2" and "ecoli" chip (please refer to the URL). I was wondering if these chips are different versions to the one I am using, in which case I can probably use them . Can anybody help me on this !! Many thanks