b'PCR reagents DNA polymerase is an essential component forFidelityPCR because of its key role in synthesizing new DNAThe fidelity, or proofreading capability, of a DNA strands. Because of the sensitive and specific nature ofpolymerase is based on its 3 to 5 exonuclease activity, PCR, it is important to choose high-quality enzymes andwhich corrects misincorporated nucleotides. This reagents to produce optimal results. The following arefunction is critical in applications such as cloning, things to consider when choosing PCR enzymes. sequencing, and site-directed mutagenesis, for accurateDid you know?replication of DNA sequences.The residual bacterial DNA in recombinant Specificity PCR enzymes poses challenges in microbial genome analysis, such as accurately Nonspecific amplification is one of the major hurdles inProcessivity detecting bacterial strains by 16S rRNA PCR, since it can drastically impact yield and sensitivityA DNA polymerases processivity is defined as thegene sequences. To enable confidence and of target amplification. One way to help reducenumber of nucleotides being incorporated in a singlesuccess in microbial PCR assays, choose nonspecific amplification is through the use of a hot- binding event. This property often reflects synthesis ratePCR enzymes with controlled low levels of start DNA polymerase, which utilizes an antibody orand speed, as well as affinity for its substrates. Therefore,residual bacterial and human genomic DNA. PCRchemical modification so that the polymerase becomeshighly processive DNA polymerases are beneficial toFind out more at active only at the high temperature of the denaturationamplify challenging templates such as long, GC-rich, orthermofisher.com/broad-range-pcrstep. In addition to improving specificity, a hot-start DNAinhibitor-containing DNA.polymerase increases yield and allows convenient room temperature setup for high-throughput applications. Primer annealing temperatureThe primer annealing temperature of each DNA fragment Thermostability to be amplified often needs optimization when designing Since thermal cycling is a key feature of the conditionsa PCR protocol. To help simplify annealing and enable that enable the repetitive chain reaction of amplifyingco-cycling of PCR assays, consider a DNA polymeraseHelpful tipDNA, thermostability of the DNA polymerase to bewith a reaction buffer that allows a universal annealingDirect PCR is a way to help simplify PCR used is also an important feature. Highly thermostabletemperature of 60C for primers. experiments, save time, and prevent sample loss in the workflow. Direct PCR allows you DNA polymerases are recommended for amplifyingto amplify target sequences directly from the GC-rich or long templates that often require prolongedsamples without the need to first isolate and high-temperature reactions. purify the DNA.Find out more atthermofisher.com/direct-pcrFind out more at thermofisher.com/pcrenzymes 26 Contents'