At Bitesize Bio, Shoba Anantha discusses how UNG can be useful in PCR analysis. Amplicons generated during PCR have dUTPs incorporated in them, Anantha notes, and UDG, the enzyme encoded in UNG, targets those dUTPs. If those amplicons are a source of contamination, using UDG before any other PCR reaction will target and make those sites abasic so that they will not "serve as good templates for Taq polymerase" while the original template will remain untouched. Anantha wonders whether UNG would be useful in real-time PCR and says that "false-positive result is often not from amplicon contamination, but due to primary sample DNA contamination" and says UNG won't be effective in that case.
Oct 12, 2010