qPrimerDB BLAST is a set of tools built with NCBI-BLAST+, and used for aligning and searching homologous sequences in the database. It supports aligning aginst multiple databases.
The NCBI-BLAST+ is buit with the latest version of NCBI BLAST+, ncbi-blast-2.9.0+-x64-linux. It supports searching against multiple databases in one run. The NCBI BLAST+ is an optimized version of the former NCBI BLAST, which is not supported by the National Center for Biotechnology Information (NCBI).