ODNBase is a database of antisense oligodeoxynucleotides targeted to mammalian mRNAs that were reported in the literature. It includes the oligo sequences tested, the measured effectiveness, the RNA that was targeted, the type of measurement assay used, the oligo concentration applied, and the reference for each oligo. It provides a searchable interface by motif content, activity level, applied concentration and RNA name. Oligo lists matching search criteria can be downloaded in a spreadsheet compatible format.