Why does PCR reaction require a primer?

Posted June 22, 2020

Answer

PCR relies on DNA polymerase to synthesize new strand of DNA complementary to the template strand. DNA polymerase can only bind to and elongate from a double-stranded region of DNA. Therefore, a primer is required in PCR to hybridize with the template DNA and offer the binding site for polymerase to initiate the polymerization.

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.