BLAST
A powerful tool for RNA-seq Analysis
BLAST
The Basic Local Alignment Search Tool (BLAST) finds regions of local similarity between sequences. The program compares nucleotide or protein sequences to sequence databases and calculates the statistical significance of matches.
Overview
BLAST (Basic Local Alignment Search Tool) is perhaps the most widely used bioinformatics program in the world. Developed by NCBI, it allows researchers to compare a query sequence with a library or database of sequences, identifying library sequences that resemble the query sequence above a certain threshold.
Key Features
- Heuristic Algorithm: Uses a faster approach than Smith-Waterman to find optimal local alignments.
- Versatility: Variants like BLASTN, BLASTP, BLASTX, TBLASTN, and TBLASTX handle different combinations of nucleotide and protein queries/databases.
- Statistical Significance: Provides E-values (Expect values) to help users judge the biological significance of matches.
Use Cases
BLAST is essential for species identification, domain location, establishing phylogeny, DNA mapping, and comparison. It serves as the first step in almost any sequence analysis workflow.