here is my problem: i have to check the entries of a column and write them out to a file if they happen to be DNA sequences ie they are exclusively composed of the letters A, T, G, C- no spaces or digits. the column also happens to have other strings that are made of word/digit/space characters. i tried if($x=~ /[ATGC]/ )then ..... however this pattern matching expression is unable to filter out the non-DNA sequences. i have also tried other expressions too convoluted to write out here.
any ideas? tia, anjan -- ============================= anjan purkayastha, phd bioinformatics analyst whitehead institute for biomedical research nine cambridge center cambridge, ma 02142 purkayas [at] wi [dot] mit [dot] edu 703.740.6939
