BLASTN

BLASTN employs the BLAST (Basic Local Alignment Search Tool) heuristic search algorithm. It ascribes significance using the statistical methods of Karlin and Altschul (1990, 1993) with a few enhancements. The BLAST programs were tailored for sequence similarity searching -- for example to identify homologs to a query sequence. The programs are not generally useful for motif- style searching. For a discussion of basic issues in similarity searching of sequence databases, see Altschul et al. (1994). BLASTN compares a nucleic acid query sequence against a nucleic acid sequence database.

Other Blast tools search sequence databases in the following ways:

  • blastp    compares protein sequences against protein sequence database(s)
  • blastx    compares the six-frame conceptual translation products of a nucleic acid sequence with a protein sequence database(s)
  • tblastn   compares a protein sequence with the six-frame conceptual translation products of a nucleic acid sequence database(s)
  • tblastx   compares the six-frame translations of a nucleic acid sequence with the six-frame translations of a nucleic acid sequence database(s)

Manual: http://www.bru.licr.org/blast/docs/blast_help.html

INPUT = Nucleic Acid Sequences.