The DNA dA-Tailing Kit efficiently adds a non-template dAMP (dA) to the 3' end of a blunt-ended DNA fragment.
This incorporated 3'-dA prevents concatemer formation and prepares the DNA fragment for subsequent ligation of adaptors or cloning vectors that have complementary 3'-dT overhangs. The Klenow Fragment (3´→ 5´ Exo-) in this kit adds the 3'-dA via its DNA polymerase activity. This enzyme lacks 5'→3' exonuclease activity and has mutations that effectively abolish the inherent 3'→5' exonuclease activity, thus preventing degradation of this 3'-dA. This kit has been optimized to prepare compatible overhangs for the next step of DNA sample preparation for next generation sequencing. The Klenow Fragment (3´→ 5´ Exo-) enzyme is also available as a stand-alone enzyme (Cat. No. E038).
One unit is defined as the amount of Klenow Fragment (3'→5' Exo-) that catalyzes the incorporation of 10 nmol of dNTP into acid insoluble material in 30 minutes at 37°C using poly(dA-dT):poly(dA-dT) as a template:primer.