Uracil DNA Glycosylase
As PCR can amplify such tiny amounts of DNA, preventing contamination is essential: even small amounts of contamination can produce false positives in your experiments. Contamination can include cross-contamination from other samples, DNA contamination from elsewhere in the laboratory, and carryover contamination from amplification products and primers used in prior PCR experiments. During PCR, deoxyuridine triphosphate (dUTP) can be substituted for deoxythymidine triphosphate (dTTP) in the synthesis of product DNA. Thus to reduce the frequency of false positive results due to amplicon contamination, one common recommendation has been to substitute dUTP for dTTP as a source of nucleotides for the PCR reaction. Amplicon DNA that has incorporated dUTP can then be degraded with uracil-DNA glycosylase prior to subsequent amplification reactions, thus preventing these molecules from producing false positive results by acting as template.
