Abstract: The present invention relates to methods and uses where a combination of (i) an enzyme exhibiting 5??3? exonuclease activity and specifically degrading 5?-phosphorylated strands of double-stranded nucleic acids is used, and (ii) one or more primer pair(s), each primer being 5? phosphorylated, in a method comprising at least a first and a second amplification reaction of a first and a second template, respectively, for preventing contamination of the second amplification reaction with amplification products of the first amplification reaction, as well as novel methods and kits using the combination. Also, the present invention relates to kits comprising the enzyme and either 5?-phosphorylated primers or a polynucleotide kinase.

Abstract: The present invention relates to methods and uses where a combination of (i) an enzyme exhibiting 5?->3? exonuclease activity and specifically degrading 5?-phosphorylated strands of double-stranded nucleic acids is used, and (ii) one or more primer pair(s), each primer being 5? phosphorylated, in a method comprising at least a first and a second amplification reaction of a first and a second template, respectively, for preventing contamination of the second amplification reaction with amplification products of the first amplification reaction, as well as novel methods and kits using the combination. Also, the present invention relates to kits comprising the enzyme and either 5?-phosphorylated primers or a polynucleotide kinase.