{% extends 'layout.html' %} {% block title %} BLAST search {% endblock title %} {% block body %}

BLAST for ASVs and Bioatlas records

Use the Basic Local Alignment Search Tool (BLAST), to find Amplicon Sequence Variants (ASVs), and associated Bioatlas occurrence records, matching your sequences and alignment criteria.


{{ sform.csrf_token }}
{% if sform.sequence.errors %}
{% else %}
{% endif %}


Nucleotide sequence(s), in fasta format, to compare against ASVs (subject sequences) in reference database 2108/50000 characters

{{ sform.sequence(id='sequence_textarea', rows=10, cols=80, maxlength='50000', class='form-control') }} {% for error in sform.sequence.errors %} {{ error }} {% endfor %}


Share of exact matches in alignment

{% if sform.min_identity.errors %}
{% else %}
{% endif %} {{ sform.min_identity(id='min_identity_input', class='form-control', type='number') }} {% for error in sform.min_identity.errors %} {{ error }} {% endfor %}


Share of aligned query bases

{% if sform.min_qry_cover.errors %}
{% else %}
{% endif %} {{ sform.min_qry_cover(id='min_qry_cover_input', class='form-control', type='number') }} {% for error in sform.min_qry_cover.errors %} {{ error }} {% endfor %}

What does this mean? This corresponds to a nucleotide BLAST (BLASTn) search filtered on -perc_identity and -qcov_hsp_perc. Query cover is calculated per High Scoring Pair (HSP), i.e. per ungapped local pairwise alignment between query and subject, and we only report the best HSP for each query-subject hit. Result fields correspond to qacc, stitle, pident, qcovhsp and evalue in tabular BLASTn output format (–outfmt=6), and rows are sorted on Query and E-value by default. E-value specifies the number of hits of similar (or higher) score that we expect to see by chance, i.e. smaller values indicate 'better' hits.


{{ sform.blast_for_seq(class='btn btn-primary', id='blast_for_seq') }}   

Tip: You may have to scroll down and wait for results to load. Then tick a checkbox to (de)select a row, toggle +/- symbols to show/hide sequences, and click bottom Show Bioatlas records button to show occurrences of selected ASV:s in the Bioatlas. You can also download search results as Excel/CSV, and use taxonID column to link these to Bioatlas records.

{% if rform %}
{{ rform.csrf_token }}

taxonID (Bioatlas link) Query Subject Id (%) Cov (%) E-value Subject sequence
{% include "sbdi_post.html" %}
{% endif %} {% endblock body %}