PCR amplification of highly GC-rich DNA template after denaturation by NaOH.

a high GC-content of template DNA may constitute a significant limitation of the technique. Previously, utilization of cosolvents, formamide (2) or glycerol (3) in the PCR was reported to significantly enhance specificity of the amplification. Most recently, a general method using native but not recombinant Pfu DNA polymerase was recommended to amplify regions of very high GC content (4). In the present study, we show that template denaturation with NaOH was required for PCR amplification of