BLAST (Basic Local Alignment Search Tool), is a sequence alignments tool, which provides a powerful way to compare novel sequences with previously characterized genes. BLAST is a program that compares sequences in order to identify similarity between them. Using this program, a given sequence (the query sequence) can be compared with thousands of other sequences in international databases (blastn). The query sequence can also be compared with another given sequence (blast2seq). The databases contain information on nucleotides (DNA, RNA) or proteins. Any scientist identifying a new sequence forwards it to the databases, so that the databases are constantly being updated. BLAST was developed by the NCBI and is accessible to the public on the Internet. BLAST was developed by the NCBI and is accessible to the public on the Internet.