The National Center for Biotechnology Information has been providing
a free sequence alignment service to the public using the BLAST family
of programs for the past 15 years. Currently the service is provided
through the NCBI BLAST web server located at
http://www.ncbi.nlm.nih.gov/BLAST/.
Multiple venues are available for end users to submit search requests
to this service. This document provides a general introduction to
the NCBI BLAST server and explains how the BLAST search requests are
handled. The focus is on describing the URL encoded parameters and
their accepted values in detail. Additional information on key parameters
and their values, usage guideline, sample URLs for different searches,
and example perl scripts is also provided. This updated document includes
the parameters introduced to the new BLAST pages released on April
17, 2007.
