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PCRBIO Classic Taq FAQs

Can I use PCRBIO Classic Taq if my assay requires a specialized buffer?

The 10x PCRBIO Reaction Buffer supplied with PCRBIO Classic Taq has been developed specifically for this enzyme and we highly recommend using them together. However, PCRBIO Classic Taq should be compatible with any PCR buffer developed for use with wild-type Taq. If you use a customised buffer with PCRBIO Classic Taq, keep in mind reaction parameters such as annealing temperature and concentrations of the enzyme, template, dNTPs and MgCl2, may require optimisation.

Can PCRBIO Classic Taq be used for colony PCR?

Yes. If you’re working from bacterial colonies use a sterile tip to pick a colony and re-suspend into the 50µl PCR reaction. If working from liquid culture add 5µl of overnight culture to the final mix. Follow the general protocol and increase the initial denaturation time to 10 min at 95°C.

Can PCRBIO Classic Taq be used to amplify DNA from blood samples?

Yes. Use 2 µL blood sample to a 50 µL PCR reaction and follow the general protocol. Keep in mind blood components may inhibit the PCR reaction. Perform a serial dilution of the sample in order to find the optimal template concentration for the PCR amplification.

Can PCRBIO Classic Taq proof-read?

No. PCRBIO Classic Taq has 5’-3’ exonuclease activities, but no 3’-5’ exonuclease (proofreading) activity.

Does PCRBIO Classic Taq generate an A-tail or blunt end on my PCR product?

PCR products generated by PCRBIO Classic Taq are A-tailed and this makes it suitable for cloning into TA vectors. For further reading, see the literature1.

1  Yao, S., Hart, D. J. & An, Y. Recent advances in universal TA cloning methods for use in function studies. Protein Eng Des Sel, doi:10.1093/protein/gzw047 (2016).

My results contain a high background of non-specific amplicons or smears. What trouble-shooting suggestions do you have?

If smears are a concern, it’s good practice to ensure they are not an artifact of running agarose gel electrophoresis with sub optimal conditions. Sub optimal conditions can include high voltage or not allowing enough time for the gel to set1.

You may also need to troubleshoot the PCR reaction and consider the suggestions below2.

  • Primers should be designed to prevent primer-primer interactions and improve specificity.
  • Increase the annealing temperature or conducting an annealing temperature gradient PCR to determine the optimal annealing temperature.
  • Reduce the amount of template in the reaction. For high quality DNA, use 1–100 ng genomic DNA or ≤5 ng plasmid/lambda DNA per 50 µL reaction.
  • Reduce the number of cycles.
  • Reduce the amount of enzyme per reaction.
  • Reduce the primer concentration, but not lower than 100 nM of each primer.
  • Include DMSO in the reaction to a final concentration of 5%–10%.

1  Koontz, L. Agarose Gel Electrophoresis. Laboratory methods in enzymology : DNA. First edition. edn, Vol. 529 35-45 (2013).

2  Lorenz, T. C. Polymerase chain reaction: basic protocol plus troubleshooting and optimization strategies. J Vis Exp, e3998, doi:10.3791/3998 (2012).

My results show a very low yield. What trouble-shooting suggestions do you have?

You may want to consider the suggestions below and also refer to the literature1.

  • Optimise the annealing temperature in an annealing temperature gradient PCR.
  • Increase the amount of template in the reaction.
  • Increase the number of cycles.
  • Increase the amount of enzyme per reaction.
  • Increase the primer concentration, but do not exceed 1 µM of each primer.
  • Try a fresh dNTP solution.
  • Optimise the MgCl2

1  Lorenz, T. C. Polymerase chain reaction: basic protocol plus troubleshooting and optimization strategies. J Vis Exp, e3998, doi:10.3791/3998 (2012).

What are the storage recommendations for PCRBIO Classic Taq?

On arrival the kit should be stored at -20°C. Avoid prolonged exposure to light. If stored correctly the kit will retain full activity for 12 months. This kit can be stored at 4°C for 1 month.

What is the difference between PCRBIO Classic Taq and PCRBIO Taq DNA Polymerase?

PCRBIO Classic Taq enzyme is provided with 10x PCRBIO Classic Buffer, with the buffer containing 30 mM MgCl2. dNTPs are sold separately and must be added to the final reaction. PCRBIO Taq DNA Polymerase is provided with 5x PCRBIO Reaction Buffer, with the buffer containing both MgCl2 and dNTPs. Additionally, PCRBIO Taq DNA Polymerase is available as a 2x Mix for extra convenience, with and without a red dye for direct loading on agarose gels.

What is the error rate of PCRBIO Classic Taq?

The enzyme has an error rate of approximately 1 error per 2.0 x 10⁵ nucleotides incorporated.

What is the recommended extension time for PCRBIO Classic Taq?

15 seconds per kilobase (kb) for amplification from eukaryotic DNA with amplicons between 1kb and 6kb. For shorter amplicons a 1 second extension is sufficient.