Taq DNA polymerase Unis

Product description

Taq DNA polymerase Unis is an alternative to Taq DNA polymerase (Cat. No. T032-T034). Difference between these two products is in difference in enzyme storage buffer which enhances stability and efficiency of the enzyme. Occasional amplification of nonspecific fragments can be prevented by enhanced dilution of the enzyme.

Taq DNA polymerase

• Taq DNA polymerase is a thermostable enzyme isolated from Thermus aquaticus. The enzyme catalyzes synthesis of complementary DNA strand in the 5’->3’ direction and also possesses a 5’->3’ exonuclease activity. During amplification of DNA fragments, Taq polymerase adds at 3’ end an adenosine overhang. This can be utilized for cloning of PCR-generated DNA fragments. Advantage of the enzyme is its high processivity (amplification of 1000 base pairs takes < 1 min). Disadvantage of the enzyme is that it lacks a 3’->5’ exonuclease proofreading activity and this accounts for high error rate [about 1 error to 10⁵ - 10⁶ base pairs (bps)]. The major usage of the enzyme is in diagnostic analysis  for amplification of DNA fragments up to 5000 bps. 

Technical data

Components and packaging

• Taq DNA polymerase Unis is supplied at a  concentration 5 U/µl. Basic packaging is 1 tube with 500 U/100 µl (T037), 5 tubes with 500 U/100 µl (T038) or 10 tubes with 500 U/100 µl (T039).
• Each tube of Taq DNA polymerase Unis is accompanied by a tube with 10 x concentrated react buffer containing MgCl₂ (1.5 ml). If different concentration of  MgCl₂ is required, a tube with 10x concentrated reaction buffer without MgCl₂ (1.5 ml) and a tube with 25 mM MgCl₂ (0.5 ml) should be ordered (Cat. No. T035).

Storage

• At temperature -20^oC ± 5°C. Material can be repeatedly defrosted.

Composition

• Storage buffer for Taq DNA polymerase Unis: 20 mM HEPES (pH 7.9 at 25^oC), 100 mM KCl, 0.1 mM EDTA, 1 mM DTT, 0.5 mM PMSF, stabilizers, 50% glycerol.
• 10x reaction buffer: 100 mM Tris-HCl, pH  8.8 (at 25^oC), 500 mM KCl, 1% Triton X-100, 15 mM MgCl₂.

Activity

• One unit is defined as the amount of enzyme, which catalyzes incorporation of 10 nmol dNTPs within 30 min at 72^oC into trichloracetic acid precipitable material. Reaction conditions are as follow: 10 mM Tris-HCl (pH 8.8 at 25^oC), 50 mM KCl, 0.1% Triton X-100, 1.5 mM MgCl₂, 200 µM dATP, dCTP, dGTP and [α-³²P]dTTP, 50 µg/ml denatured cDNA, 0.5 µM primer and 0.2 – 0.5 U of enzyme in the volume of 50 µl.

Purity and quality control

• Purity of Taq DNA polymerase Unis is tested by SDS-PAGE. After staining with Coomassie blue, enzyme migrates as the major band of  94 kDa. Material is nuclease free.
• Each batch of Taq DNA polymerase Unis is tested for its ability to amplify DNA fragment from mammalian genomic DNA by PCR. The results are verified by electrophoresis in agarose gel in the presence of ethidium bromide; only DNA band of the expected size is present.