DNA Polymerase I/DNase I is an optimized mixture of both enzymes for efficient nick translation of DNA.

Application: Labeling DNA with either radiolabeled or biotinylated nucleotides.

Source: DNase I is purified from bovine pancreas; DNA Polymerase I from E. coli λ lysogen NM 964.

Performance and Quality Testing: Performance tested in nick translation reaction.

Unit Definition: One unit of DNA Polymerase I in the absence of DNase I incorporates 10 nmol of total deoxyribonucleotide into acid-precipitable material in 30 min. at 37°C using a template•primer.

Unit Reaction Conditions: 50 mM potassium phosphate (pH 7.5), 6.7 mM MgCl₂ , 1 mM 2-mercaptoethanol, 80 µg/ml template•primer, 32 µM dTTP, 69 nM [³H]dTTP, and enzyme in 100 µl for 30 min. at 37°C.