Blast data base
Select which data base should be used to search. The RefSeq should be the
preferred one, only if insufficient results can be found the full NCBI nt data
base should be used.
The RefSeq "Representative Genome Database" is a well curated data base which
only contains genomes, while the nt (non-redundant nucleotide) data base
contains nucleotide sequence from a variety of sources. The RNAcode analysis
is based on an alignment of genomic regions, hence the RefSeq data base is
the preferable choice. Yet for some phylas the RefSeq data base might be
sparse in such cases the nt data base should be chosen.