BLAST can be used for a lot of different purposes. A few of them are
- Looking for species. If you are sequencing DNA from unknown species, BLAST may help identify the correct species or homologous species.
- Looking for domains. If you BLAST a protein sequence (or a translated nucleotide sequence) BLAST will look for known domains in the query sequence.
- Looking at phylogeny. You can use the BLAST web pages to generate a phylogenetic tree of the BLAST result.
- Mapping DNA to a known chromosome. If you are sequencing a gene from a known species but have no idea of the chromosome location, BLAST can help you. BLAST will show you the position of the query sequence in relation to the hit sequences.
- Annotations. BLAST can also be used to map annotations from one organism to another or look for common genes in two related species.