If you have any questions or concerns, please contact blast-help@ncbi.nlm.nih.gov

Key Features of BLAST:
1. Sequence Comparison: BLAST searches for local alignments between the query sequence and sequences in a database. It identifies regions of similarity, which can help infer functional and evolutionary relationships.

2. Speed and Efficiency: BLAST uses heuristic algorithms, making it faster than exhaustive search methods, suitable for large-scale database searches.

3. Versatility: There are several versions of BLAST for different types of sequence comparisons:
- blastn: Compares a nucleotide query sequence against a nucleotide sequence database.
- blastp: Compares a protein query sequence against a protein sequence database.
- blastx: Compares a nucleotide query sequence translated in all reading frames against a protein sequence database.
- tblastn: Compares a protein query sequence against a nucleotide sequence database translated in all reading frames.
- tblastx: Compares the six-frame translations of a nucleotide query sequence against the six-frame translations of a nucleotide sequence database.

4. Scoring and E-value: BLAST results are scored based on the quality and length of the alignments. The E-value (expect value) indicates the number of alignments one can expect to find by chance, with lower E-values representing more significant matches.

5. Output Formats: BLAST provides results in various formats, including plain text, HTML, XML, and JSON, making it adaptable for different types of analyses and integrations with other tools.

Applications of BLAST:
- Genomic Research: Identifying genes, understanding genetic diversity, and mapping genome sequences.
- Protein Function Prediction: Inferring the function of unknown proteins by comparing them to known protein sequences.
- Evolutionary Studies: Exploring evolutionary relationships between organisms by comparing their genetic material.
- Medical Research: Identifying pathogens, understanding disease mechanisms, and developing treatments by comparing sequences of interest.

Overall, BLAST is an essential tool in bioinformatics, offering a reliable and efficient way to analyze and interpret biological sequence data.

The Representational State Transfer (REST) sample clients are provided for a number of programming languages. For details of how to use these clients, download the client and run the program without any arguments.

For details see Environment setup for REST Web Services and Examples for Perl REST Web Services Clients pages.

Alternatively, use one liner perl script:

perl -ne 'if(/^>(\S+)/){$c=$i{$1}}$c?print:chomp;$i{$_}=1 if @ARGV' GIs.txt >sequence.fasta

where GIs.txt contains a list of GIs or accession IDs.

(from :http://edwards.sdsu.edu/labsite/index.php/robert?start=5)

Address of the bookmark: http://edwards.sdsu.edu/labsite/index.php/robert/380-ncbi-sequence-or-fasta-batch-download-using-entrez

The NCBI Datasets datasets command line tools are datasets and dataformat .

Use datasets to download biological sequence data across all domains of life from NCBI.

Use dataformat to convert metadata from JSON Lines format to other formats.

Conda download:

https://anaconda.org/conda-forge/ncbi-datasets-cli

Buld Download

 https://www.ncbi.nlm.nih.gov/datasets/builder/?tax_id=29979

Address of the bookmark: https://www.ncbi.nlm.nih.gov/datasets/docs/v1/quickstarts/command-line-tools/

• New ProSplign tool integrated with Genome Workbench (Tutorial, Video)
• New export function for BAM/cSRA coverage graphs (Tutorial)
• New export function for alignments GFF3 format ((Tutorial))
• Tree View: implemented new export mode based on selections (tutorial coming)
• Tree View: added support for distance based circular trees
• Tree View: new rooting mode (Midpoint Root) results in more balanced trees (Tutorial)
• Tree View: added possibility to right-click on an edge between two nodes and "Place Root at Middle of Branch" – to re-root at mid-branch (Tutorial)

EDirect also provides an argument-driven function that simplifies the extraction of data from document summaries or other results that are returned in structured XML format. This can eliminate the need for writing custom software to answer ad hoc questions. Queries can move seamlessly between EDirect commands and UNIX utilities or scripts to perform actions that cannot be accomplished entirely within Entrez.

Address of the bookmark: https://www.ncbi.nlm.nih.gov/books/NBK179288/

https://www.ncbi.nlm.nih.gov/research/groups/koonin/