Hi, I am new to limma and am having problems reading Scanarray Express .csv files into limma via read.maimages. I am running R version 2.4.1 and limma version 2.9.17. I tried... >RG<-read.maimages(files, source="scanarrayexpress", path=path) Error in readGenericHeader(fullname, columns = columns, sep = sep) : Specified column headings not found in file In addition: Warning messages: 1: input string 1 is invalid in this locale in: grep(pattern, x, ignore.case, extended, value, fixed, useBytes) 2: input string 1 is invalid in this locale in: grep(pattern, x, ignore.case, extended, value, fixed, useBytes) 3: input string 1 is invalid in this locale in: grep(pattern, x, ignore.case, extended, value, fixed, useBytes) 4: input string 1 is invalid in this locale in: grep(pattern, x, ignore.case, extended, value, fixed, useBytes) Adding in the column names doesn't seem to help, as I get the same error when I try this (I have tried using "R"/"G" instead of "Rf"/"Gf" as well). >RG<-read.maimages(files, source="scanarrayexpress", path=path, columns=list(Rf="Ch1 Median", Rb="Ch1 B Median", Gf="Ch2 Median", Gb="Ch2 B Median")) I have also tried including sep="," and using source="generic". Removing all the of header lines before the actual column names in the scanarray output file doesn't fix the problem either. What am I doing wrong? Thanks, Sarah