UNIT 19.3 Sequence Similarity Searching Using the BLAST Family of Programs

Database sequence similarity searching is carried out thousands of times each day by researchers worldwide and has become a very valuable tool. Over the years, a number of algorithms have been implemented to facilitate database searching. The BLAST (Basic Local Alignment Research Tool) family of sequence similarity search programs allows searches to be done quickly and easily, but with sensitive, yet rigorous statistical expectations. In this unit, which is a completely new version of its predecessor of the same title, the user learns how to access the databases, determine the correct searching strategies, and apply examples of BLAST searches to his or her own data.