Thanks for the response! The multi fasta file I put up is a very simple file but I know, from working with fasta files, that sometimes the titles can be complex and may be divided in strange ways. Sometimes there isn't a space between the name and the rest of the information but instead other symbols that can be used as separators. That's the reason why I had all those non-word symbols. But, as you say, it is not necessary if I know what I want to throw away. This really helps! Thanks again!