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Preventing unspecific PCR Products

Standard thermostable polymerases (e.g. Taq) have optimal performance around 70°C. Yet, moderate enzymatic activity at room temperature creates unspecific products.

Hot Start Technology reduces the generation of undesired fragments and allow for PCR setup at room temperature. Inhibition of Hot Start Polymerases at ambient temperature prevents unspecific reactions before heating begins. Heat-induced inhibitor release takes place during the first step of PCR (Fig. 1).

Fig. 1: Detection of genetically modified Roundup Ready® soy (Monsanto)

Fig. 1: Detection of genetically modified Roundup Ready® soy (Monsanto) down to 0.1 % in soybean flour was compared for Hot Start Pol and conventional Taq Pol. Formation of by-product and associated risk of false positive detection is greatly reduced by Hot Start Pol. Assay: Amplification of genomic DNA, 210 bp fragment of soy transgene, 150 ng DNA / reaction, 1.25 units Hot Start Pol / reaction, 95 °C, 2 min; 35x (95 °C, 30 sec; 56 °C, 30 sec; 72 °C, 30 sec); 72 °C, 4 min.


Chemically modified polymerases need a heat activation step which can lead to DNA damage. In contrast, aptamers or antibodies inhibit Jena Bioscience Hot Start Polymerases and activation occurs during the initial denaturation step of the PCR, eliminating DNA damage.

Hot Start Polymerase Ab+ is most strongly inhibited at room temperature and gives maximum specificity. However, antibodies are of animal origin. In order to prevent mammalian nucleic acid contamination, Jena Bioscience offers Hot Start Polymerase, aptamer blocked based on a fully synthetic inhibitor.

Antibody based Hot Start TechnologyAptamer based Hot Start Technology
Hot Start Polymerase Ab+ (PCR-213)
Thermus aquaticus, recombinant, E. coli
Hot Start Polymerase (PCR-212)
Thermus aquaticus, recombinant, E. coli
Hot Start Core Kit Ab+ (PCR-216)
Kit of Hot Start Pol, dNTPs and reaction buffer
Hot Start Core Kit (PCR-215)
Kit of Hot Start Pol, dNTPs and reaction buffer
  Crystal Hot Start Master (2x) (PCR-167)
Master mix, ready-to-use
 Ruby Hot Start Master (2x) (PCR-165)
Master mix, ready-to-use for direct-to-gel analysis