Benzonase^® Nuclease is a genetically engineered endonuclease from Serratia marcescens. It degrades all forms of DNA and RNA (single stranded, double stranded, linear and circular) while having no proteolytic activity. It is effective over a wide range of conditions and possesses an exceptionally high specific activity. The enzyme completely digests nucleic acids to 5′-monophosphate terminated oligonucleotides 2 to 5 bases in length (below the hybridization limit), which is ideal for removal of nucleic acids from recombinant proteins, enabling compliance with FDA guidelines for nucleic acid contamination. The ability of Benzonase to rapidly hydrolyze nucleic acids makes the enzyme an excellent choice for viscosity reduction to reduce processing time and increase yields of protein. For example, the enzyme is compatible with BugBuster^® and PopCulture^® Protein Extraction Reagents and can therefore be added along with these reagents to eliminate viscosity and remove nucleic acids from E. coli extracts. The enzyme consists of two subunits of 30 kDa each. It is functional between pH 6 and 10 and from 0-42°C and requires 1-2 mM Mg²⁺ for activation. The enzyme is also active in the presence of ionic and non-ionic detergents, reducing agents, PMSF (1 mM), EDTA (1 mM) and urea (relative activity depends on specific conditions). Activity is inhibited by > 150 mM monovalent cations, > 100 mM phosphate, > 100 mM ammonium sulfate, or > 100 mM guanidine HCl. Benzonase Nuclease is available in ultrapure (> 99% by SDS-PAGE) and pure (> 90%) grades at a standard concentration of 25 U/µl and at a high concentration (HC) of 250 U/µl. Both preparations are free of detectable protease and have specific activity > 1 × 10⁶ U/mg protein. The > 99% purity grade is tested for endotoxins and contains < 0.25 EU/1000 units. The product is supplied as a 0.2 µm filtered solution in 50% glycerol. Store at -20°C. Total endotoxin: < 0.25 EU/1,000 units. Purity: > 90% by SDS-PAGE.