BLAST workshop summary

NCBI BLAST is a useful tool for exploring evolutionary relationships between biological sequences.

You learned how to:

• use smaller databases and modify them using limits and filters to get more meaningful results
• quickly identify sequences and find orthologs in species closely related to the source of the query with megablast
• find orthologs in closely related species with blastn
• find more distant homolog with protein level searches (blastp, tblastn, blastx, and PSI-BLAST)
• make a multiple sequence alignment and a phylogenetic (sequence) tree with COBALT and the Tree Viewer
• use the experimental taxonomic nt and ClusteredNR databases to work with a reduced database for faster more informative results

Remember: Search the smallest database likely to contain the target of interest!

For any questions about BLAST and to provide feedback, especially on the experimental database, write to blast-help@ncbi.nlm.nih.gov. Include a recent RID when reporting problems.