Uracil DNA Glycosylase (uracil-N-glycosylase) removes uracil residues from the sugar moiety of single- and double-stranded DNA without destroying the phosphodiester backbone, preventing its use as a hybridization target or as a template for DNA polymerases. UDG will not remove uracil from RNA.

Applications: Helps to eliminate carryover contamination in PCR, resulting in fewer false positive results (1,2) for cloning PCR fragments (3).

Source: Purified from E. coli expressing the E. coli ung gene on a plasmid (4,5).

Performance and Quality Testing: Exonuclease, endonuclease, and phosphatase assays.

Unit Definition: One unit catalyzes the release of 1 nmol of free uracil from ³H-poly(dU) in 1 h at 37°C.

Unit Reaction Conditions: 30 mM Tris-HCl (pH 8.3), 50 mM KCl, 5 mM MgCl₂ , 4 μg/ml ³H-poly(dU)n at 7 x 10 5 cpm/μg, and 1 unit of
enzyme in 50 μl for 10 min. at 37°C (4).