Nucleotide to Nucleotide BLAST (blastn)

Request a New BLAST

Enter one or more queries in the top text box or use the browse button to upload a file from your local disk. The file may contain a single sequence or a list of sequences. In both cases, the data must be in FASTA format.

Show an Example Sequence

Enter FASTA sequence(s)

Or upload your own query FASTA:

The file should be a plain-text FASTA (.fasta, .fna, .fa, .fas) file. In other words, it cannot have formatting as is the case with MS Word (.doc, .docx) or Rich Text Format (.rtf). It cannot be greater than 500MB in size. Don't forget to press the Upload button before attempting to submit your BLAST.

Choose Search Target

Choose from one of the nucleotide BLAST databases listed below.

Nucleotide BLAST Databases:

Advanced Options

General parameters

Max target sequences:

e-Value (Expected Threshold)

Expected number of chance matches in a random model. This number should be give in a decimal format. More Information | Expect value video tutorial

Word size:

Max matches in a query range

Scoring parameters

Match/Mismatch Scores:

Gap Costs: