IsoPol SD+™


IsoPol™ SD+ is a DNA polymerase with stronger strand displacement and higher salt tolerance, compared to ArcticZymes first IsoPol™.

IsoPol SD+ - figure 1
Figure 1: Temperature optimum of IsoPol™ SD+. The enzyme was assayed at the indicated temperatures in 10 mM Tris-HCl pH 8.5, 100 mM NaCl, 5 mM MgCl2, 700 μg/mL denatured herring sperm DNA, 33 μM dNTPs (each), 0.125 μM [3H]-dTTP, 0.8 mM DTT, 0.02% Triton X-100. Samples were incubated for 1 and 5 minutes. Activity was determined measuring radioactive decay [CPM] of incorporated [3H]-dTTPs in acid insoluble material. ΔCPM/min between time point one and two were used as measure of activity. Results are depicted as relative to maximum. The dashed line represents a stipulation of curve progression based on IsoPol™ DNA Polymerase


Unit Definition: One unit is defined as the amount of enzyme that will incorporate 10 nmol of dNTP into acid insoluble material in 30 minutes at 37°C. IsoPol™ SD+ exhibits a specific activity of ~7 500 U/mg.

Strand-displacement activity: IsoPol™ SD+ exhibits stronger strand-displacement activity than other polymerases at 25°C and 37°C.

IsoPol II - figure 2
Figure 2: Polymerase activity of IsoPol™ DNA Polymerase and IsoPol II™ as function of NaCl concentrations in 10 mM Tris-HCl pH 8.5 (@ 25°C), 5 mM MgCl2, 0.72 µg/µl denatured herring-sperm DNA, 33 µM dNTPs (incl. [3H]-dTTPs), 0.4 µg/ml IsoPol or IsoPol II (6.5 nM). Incubation temperature/time: 37 °C/10 min. Activity determination by counting decay events of incorporated [3H]-dTTPs in acid insoluble DNA product in counts per minute [CPM]. Data represented relative to highest activity of each polymerase. Error bars represent 1x standard deviation of biological replicates.

Features: IsoPol™ SD+ exhibits 5’-3’ polymerase activity and lacks 3’-5’ exonuclease activity. The 5’-3’ exonuclease domain is truncated, thus the enzyme also lacks 5’-3’ exonuclease activity.

Inactivation: IsoPol™ SD+ can be heat inactivated at temperatures above 50°C.

Optimal reaction conditions: Optimal performance is achieved in a pH 8.5 buffer supplemented with 4-6 mM MgCl2 and 100-350 mM salt (NaCl or KCl), at 37°C.

Storage and Stability

The enzyme is stable at -20°C for 2 years in the supplied storage buffer. The enzyme tolerates at least four freeze-thaw cycles (-80°C) without loss of activity. Storage of the enzyme at 200 mM NaCl is recommended for high concentration samples.

Quality Control

ArcticZymes is dedicated to the quality of our products. IsoPol™ SD+ is manufactured at our ISO 9001 certified facility in Norway.

dsDNA endonuclease activity

25 U IsoPol™ SD+ was incubated with a supercoiled plasmid (1 µg) for 4 hours at 37°C. Agarose gel electrophoresis did not reveal any transformation of closed circular DNA to nicked DNA.

ssDNA endonuclease activity

25 U IsoPol™ SD+ was incubated with M13 ssDNA (0.5 µg) for 4 hours at 37°C. Agarose gel electrophoresis did not reveal any visible signs of ssDNA degradation.

Additional Data and Information

We are pleased to provide data and information relating to IsoPol™ SD+. The Product is an Early Access Product, and further product information will be generated continuously. Available data includes; buffer and storage conditions, optimal conditions, activity processivity, and strand displacement data.

We appreciate suggestions for product modifications.

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