Protein to Nucleotide BLAST (tblastn)

If you use the textbox, please enter the sequence using single line FASTA format. If you have problems using BLAST tool, please change "Max target sequences" under the "Advanced Options" to a lower value.

Request a New BLAST

Enter Protein Query Sequence

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)

Enter query sequence(s) in the text area.

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 2MB 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:

Select the maximum number of aligned sequences to display

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 vedio tutorial

Word size:

The length of the seed that initiates an alignment

Scoring parameters

Matrix

Assigns a score for aligning pairs of residues, and determines overall alignment score.

Gap Costs:

Cost to create and extend a gap in an alignment.