tool to design flanking oligo nucleotides for DNA amplification

 Primer3 picks primers for Polymerase Chain Reactions (PCRs), considering as
 criteria oligonucleotide melting temperature, size, GC content and
 primer-dimer possibilities, PCR product size, positional constraints within
 the source sequence, and miscellaneous other constraints. All of these
 criteria are user-specifiable as constraints, and some are specifiable as
 terms in an objective function that characterizes an optimal primer pair.