
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. BLAST® can be used to infer functional and evolutionary relationships between sequences as well as help identify members of gene families. (description from NLM/NCBI)
Getting started and guides:
For a detailed description of the statistics behind local alignment calculations that are used in BLAST, the following YouTube videos are available.
- The Statistics of Local Pairwise Sequence Alignment, Part 1 Stephen Altschul January 22, 2015
- The Statistics of Local Pairwise Sequence Alignment, Part 2 Stephen Altschul January 29, 2015