Primer3Plus

Primer3Plus is a modern, user-friendly web interface for the widely-used Primer3 primer design algorithm. It allows researchers to paste or upload a DNA template sequence, visually mark target regions, excluded regions, and included regions directly on the sequence, and then generate optimized PCR primer pairs. Features include configurable melting temperature, GC content, product size ranges, advanced penalty weights, and internal hybridization probe (oligo) design. Developed and supported by EMBL, it is one of the most popular tools for primer design in molecular biology and genomics laboratories worldwide.