AAT Bioquest

Why are 2 primers needed for PCR?

Posted June 22, 2020


Two primers, forward primer and reverse primer, are used in each PCR reaction, which are designed to flank the target region for amplification. Two complementary single strands of DNA are released during denaturation. The forward primer binds to the template DNA, while the reverse primer binds to the other complementary strand, both of which are amplified in PCR reaction. If only one primer is used, the process is called “asymmetric PCR”. Only one strand of the double-stranded DNA will be amplified, and only one new copy is synthesized per cycle, which is unable to achieve exponential amplification.

Additional resources

6-ROX glycine *25 uM fluorescence reference solution for PCR reactions*

Chen, S. C., Halliday, C. L., & Meyer, W. (2002). A review of nucleic acid-based diagnostic tests for systemic mycoses with an emphasis on polymerase chain reaction-based assays. Medical mycology, 40(4), 333-357.

Chuang, L. Y., Cheng, Y. H., & Yang, C. H. (2013). Specific primer design for the polymerase chain reaction. Biotechnology letters, 35(10), 1541-1549.