Taq DNA Polymerase
Taq DNA polymerase is a biocatalyst that can be used for PCR amplification of DNA fragments, DNA labeling, primer extension, sequence determination, etc.
94 kDa (approx)
Optimum active temperature:
at -20 ℃ for two years
Dry ice (-70 ℃)
- Category: PCR Enzymes
Taq DNA Polymerase,PCR Enzymes
What is Taq DNA Polymerase?
Taq DNA polymerase, or Taq polymerase, is a biocatalyst that is involved in the attachment of nucleotides to synthesize DNA—just like any other polymerase.
Taq DNA Polymerase is an engineered version of Taq DNA Polymerase. The enzyme consists of a single polypeptide with a molecular weight of approximately 94 kDa. Taq DNA Polymerase has 5’-3’ DNA polymerase activity and 5’-3’ exonuclease activity. It lacks 3’-5’ exonuclease activity.
Taq polymerase is a homolog of the Pol I DNA polymerase found in E. coli and is an 832 amino acid protein with a molecular weight of 94 kDa (approximately).
But what makes this polymerase unique is that it is a thermostable enzyme that can withstand high-temperature conditions, unlike most known enzymes that only work well at 37°C (body temperature).
The optimal temperature at which Taq polymerase is most active is 70-75°C, and it shows thermostability even at 92°C.
How was Taq DNA polymerase discovered?
Taq DNA polymerase was the first thermostable DNA polymerase to be discovered, originally extracted from a strain of thermophagus (thermus aquaticus) isolated from hot springs by Saiki et al.
The enzyme can withstand high temperatures, and its residual activity is greater than 90% of the original after 2h reaction at 70°C, 60% of the original after 2h at 93°C, and 40% of the original after 2h at 95°C. %;
In molecular cloning, Taq DNA polymerase can be used for DNA sequence determination and can use polymerase chain reaction (polymerase chain reaction, PCR) to amplify specific DNA fragments in vitro.
In the PCR process, since Taq DNA polymerase is not inactivated during the denaturation step (about 94°C), it can directly enter the second cycle, so it is not necessary to re-add new enzyme in each cycle, which makes Taq DNA polymerase a PCR product Unique enzymes in the reaction.
Properties of Taq DNA Polymerase:
• Extension rate is about 6 kb/min.
• Template-independent “A” can be generated at the 3′ end of the PCR product. PCR products can be directly cloned into pEASY®-T vectors.
• Amplification of genomic DNA fragment up to 4 kb.
Taq DNA polymerase with a relative molecular mass of 94 has higher activity, about 200,000 U/mg, and has a higher optimum temperature of 75 to 80°C when synthesizing DNA. Although Taq DNA polymerase has limited ability to synthesize DNA above 90°C, it is still relatively stable at high temperatures.
Experiments have shown that at 92.5℃, 95℃ and 97.5℃, the Taq DNA polymerase in the PCR mixture can still maintain about 50% of the activity after 130 min, 40 min and 5-6 min respectively, and its half-life is long.
Taq DNA polymerase has high processing and synthesis characteristics. At the optimum reaction temperature, the rate of dNTP incorporation is 35-100 nt/(s.enzyme molecule), and the longest amplification length can reach 7.6 kb. Under low-temperature conditions, the activity of Taq DNA polymerase is significantly reduced, resulting in a hindered ability of the enzyme to extend in local secondary structure regions within the template or a change in the ratio of the forward rate constant to the dissociation constant. At higher temperatures (above 95°C), there is little DNA synthesis; in vitro, the rate of DNA synthesis at higher temperatures is limited by the stability of the primer or the duplex structure of the primer strand and the template strand.
Since the optimal reaction temperature of Taq DNA polymerase is as high as 75-80 °C, the annealing temperature and extension temperature can be appropriately increased, which limits the appearance of non-specific amplification products and increases the specificity of PCR reaction.
Applications of Taq DNA Polymerase:
Geneture Taq DNA Polymerase applications:
• Routine PCR
• High throughput PCR
• Colony PCR
Taq DNA polymerase can be used for PCR amplification of DNA fragments, DNA labeling, primer extension, sequence determination, blunt end addition of A, etc. The product can be directly used for T/A vector cloning.
The application of Taq DNA polymerase in PCR, although common Taq DNA polymerase has been widely used, there are still some shortcomings. Various laboratories have carried out different forms of modification in response to the deficiency of Taq DNA polymerase to reduce or eliminate the 5'→3' exonuclease activity of the enzyme and improve the enzyme's continuation, fidelity, specificity and heat resistance. Wait. Taq DNA polymerase was modified at the gene level by site-directed mutagenesis and deletion mutagenesis to eliminate the 5'→3' exonuclease activity of the enzyme and reduce the resistance of Taq DNA polymerase to ddNTPs. Protein expression and purification.
Supplier of Taq DNA polymerase:
GENETURE is a group company focus on the field of clinical diagnosis and life sciences,provide one stop solution of Nucleic Acid Extraction and Analysis,including solution of COVID-19. Our main products including Nucleic acid extraction kit,Nucleic acid extractor,Magnetic beads,PCR kit, PCR system.etc.
If you have any requirements or questions about Taq DNA polymerase, please feel free to contact us.
at -20 ℃ for two years
Dry ice (-70 ℃)
|10 x Taq Buffer||1.2ml x 1||1.2 ml ×6|
|2.5 mM dNTPs||- / 800 μl ×1||- / 800 μl ×6|
|6 x DNA Loading Buffer||1 ml×1||1 ml ×2|
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