USER® Enzyme
cloned at NEB recombinant neb31 37 No

A thermolabile version is also available, Thermolabile USER II Enzyme (NEB #M5508).

We are excited to announce that we are in the process of switching all reaction buffers to be BSA-free. Beginning April 2021, we will be gradually transitioning to buffers containing Recombinant Albumin (rAlbumin) for restriction enzymes and some DNA modifying enzymes. All information on the website has been updated to reflect this change. Find more details at

USER (Uracil-Specific Excision Reagent) Enzyme (1) generates a single nucleotide gap at the location of a uracil residue.

Applications of USER include:

  • Directional RNA Seq
  • NEBNext adaptor cleavage
  • USER cloning


USER Enzyme

Uracil DNA glycosylase (UDG) catalyzes the excision of a uracil base, forming an abasic (apyrimidinic) site while leaving the phosphodiester backbone intact. The lyase activity of Endonuclease VIII breaks the phosphodiester backbone at the 3´ and 5´ sides of the abasic site so that base-free deoxyribose is released. USER (Uracil-Specific Excision Reagent) Enzyme, combines these two enzymatic activities to generate a single nucleotide gap at the location of a uracil residue.

Catalog # Concentration Size List Price Your Price Quantity
M5505S 1,000 units/ml 50 units $75.00
M5505L 1,000 units/ml 250 units $303.00
Please enter a quantity for at least one size
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