DNA templates with a high proportion (>65%) of GC (guanine and cytosine) nucleotide base pairs can be difficult to amplify during PCR. This is because the strength of hydrogen bonding between these nucleobases is greater than that of the other nucleobases (adenine and thymine), and because GC-rich templates have a tendency to fold into complicated secondary structures (e.g. loops and hairpin structures). This causes GC-rich templates to be resistant to melting in the denaturation steps during PCR, preventing accurate primer binding and polymerase amplification.
10x GC-Rich PCR Enhancer is used as a PCR additive for difficult to amplify GC-rich templates. The optimised solution modifies the melting behaviour of nucleic acids, and often enhances amplification of suboptimal PCR templates with high degrees of secondary structures and GC-rich regions.