Chris, The Bio::Index modules either 'use base qw(Bio::Index::Abstract)' or 'use base qw(Bio::Index::AbstractSeq)'. Neither of these modules has an id_parser() method. Brian O. On 10/17/06 10:12 AM, "Chris Fields" <cjfields at uiuc.edu> wrote: > Do the various Bio::Index* modules share a common interface?