Hi, I am getting a similar error but with Drosophilia_2 chips: > qc.data <- qc(Data, ampli.eset) Error in qc.affy(unnormalised, ...) : I'm sorry, I do not know about chip type: drosophila2cdf FYI, here's what cdfName gives me: > cdfName(Data) [1] "Drosophila_2" and here's my system info: > sessionInfo() R version 2.1.0, 2005-05-09, i686-pc-linux-gnu attached base packages: [1] "tools" "methods" "stats" "graphics" "grDevices" "utils" [7] "datasets" "base" other attached packages: limma simpleaffy gcrma matchprobes affy reposTools "1.9.3" "2.0.13" "1.1.3" "1.0.12" "1.5.8-1" "1.5.2" Biobase "1.5.0" Would this problem be related to Dick's? Any help would be gratefully received! Cheers, Dan. -- Dan Frampton Bloomsbury Centre for Bioinformatics Dept. Computer Science University College London Gower Street London WC1E 6BT