Your regex change may be a bit too clever. We don't know for sure that the space always will be there. Looking at the OP, it's fair to assume that there always will be something though. Perhaps the next line is just ">EP40007". A better way to express what you want to express while not being as restrictive is /^>(\S)+/ which does what you want: gets the first non-space characters. Personally I'd probably do the check in two steps; one to see if there's a '>' there (assuming that /^>/ means a header line), and the next to see if the rest of the line holds a valid format. I habitually verify foreign input.

ihb