Recombinant Dr. Nuclease

Similar to MilliporeSigma Benzonase nuclease, a genetically engineered endonuclease from Serratia marcescens, Syd Labs recombinant Dr. Nuclease degrades all forms of DNA and RNA while having no proteolytic activity. The endonuclease activity is effective over a wide range of conditions and the enzyme possesses an exceptionally high specific activity.

Dr. Nuclease is a recombinant endonuclease produced in E. coli. Dr. Nuclease acts as an endonuclease that degrades both DNA and RNA in single-stranded, double-stranded, linear, circular, and super-coiled forms. Upon complete digestion, it digests all free nucleic acids present in solution into 5’-monophosphate-ended oligonucleotides with three to five bases.

Dr. Nuclease solution is used for a variety of purposes including but not limited to: viral vaccine production; viral vector production for cell and gene therapy; prevention of cell clumping; viscosity reduction in mammalian cell extracts; viscosity reduction in E. coli cell lysates for enhanced filterability; purification of protein fragments from inclusion bodies; elimination of nucleic acids from recombinant protein; sample preparation in two-dimensional gel electrophoresis.

Dr. Nuclease eliminates DNA/RNA containments in various products with ultra-speed and efficacy. Dr. Nuclease is super-effective to reduce the viscosity of cell paste or lysed solution. With great tolerance to various inhibitors of proteases used in protein purification, Dr. Nuclease reduces cell clumping in seconds, therefore improves the protein purification process and yield.

BP4200: Recombinant Dr. Nuclease (Benzonase Nuclease Alternative)

Source: E. coli-derived.
Predicted molecular mass: ~28 kDa.
Specific activity: ≥1.75 x 10^6 U/mg. One unit of Dr. Nuclease corresponds approximately to the required amount of enzyme to digest 37 μg of DNA in the reaction buffer, 50 mM Tris-HCl, pH 8.0, 1 mM MgCl2, for 30 minutes at 37°C.
Purity: ≥98% by Coomassie Blue staining method.
Formulation: 0.2 μM filtered solution (1000 units/ul) of PBS, pH 7.4, 2 mM MgCl2, 50% glycerol.
Endotoxin level: ≤0.5 EU/1000 units by LAL method.
Protease activity: No detectable protease activity using casein as substrate.

BP4200-GMP: Recombinant Dr. Nuclease (Benzonase Nuclease Alternative), GMP Grade

Source: E. coli-derived.
Predicted molecular mass: ~28 kDa.
Specific activity: ≥1.1 x 10^6 U/mg. One unit of Dr. Nuclease is defined as the amount of enzyme required to produce a change in absorbance at 260 nm of 1.0 in the time of 30 minutes, under optimum conditions with excess substrate.
Purity: ≥95% by SDS-PAGE and ≥99% by SEC-HPLC. It does not contain any antimicrobial preservatives or protein stabilizers except glycerol (of synthetic origin).
Formulation: 0.2 μM filtered solution (250 units/ul) of 20 mM Tris-HCl, pH 8.0, 2 mM MgCl2, 2 mM NaCl, 50% Glycerol.
Endotoxin level: ≤0.01 EU/1000 units following 2020 ChP 1143 USP <85>.
Protease activity: No detectable protease activity using casein as substrate.
Residual host cell protein: ≤10.0 ppm by ELISA.
Mycoplasma: negative by qPCR method.
Bioburden: negative following 2020 ChP 1105 USP <61>.
Residual heavy metal: ≤10.0 ppm following 2020 ChP 0821 USP <32>.

Shipping: Recombinant Dr. Nuclease is shipped with ice pack. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
4 weeks from date of receipt if stored at 4°C as supplied.
2 years from date of receipt if stored at -20°C as supplied.
Note: We do not recommend -70°C.

Dr. Nuclease is active under a wide range of conditions, even in the presence of ionic and non-ionic detergents, urea, and ammonium sulfate.

Table 1. The activities of Dr. Nuclease under various conditions:
Conditions    Optimal    Effective range
Mg2+    1–2 mM    1–10 mM
pH    8.0–9.2    6.0–10.0
Temperature     37 °C    0–50 °C
Dithiothreitol (DTT)    0–100 mM    >100 mM
8-Mercaptoethanol    0–100 mM    >100 mM
Monovalent cation concentration (Na+, K+, etc.)    0–20 mM    0–150 mM
PO43- concentration    0–10 mM    0–100 mM

A typical endonuclease reaction can be setup in 50 mM Tris-HCl, pH 8.0, 1 mM MgCl2 for 30 minutes at 37°C. We recommend 50 units for treating 1 mg of total DNA or RNA, or 2000 units for up to 2 L of conditioned media in 30 minutes. For other application, users should optimize their own conditions.

Optimal is defined as the conditions under which Dr. Nuclease retains >90% of its activity.

Effective is defined as the conditions under which Dr. Nuclease retains >15% of its activity.

Thermo-stability of Dr. Nuclease
The optimal temperature for degradation of nucleic acids by Dr. Nuclease is 37°C. However, the endonuclease is effective over a temperature range of 0–50°C. The endonuclease should be stored at -20 °C to prevent loss of activity. We do not recommend repeated freeze/thaw cycles nor storage at temperatures lower than -20°C. Dr. Nuclease is also stable in the lyophilized form.

Effect of guanidine HCl, EDTA, and PMSF on endonuclease activity of Dr. Nuclease
The standard assay was used to check inhibitory effect of various chemicals on endonuclease activity of Dr. Nuclease. If concentration exceeds 100 mM, guanidine HCl completely inhibits the enzyme activity. An EDTA concentration of 1 mM partially inhibits the endonuclease; a concentration of 5 mM EDTA causes a >90% loss of enzyme activity by complexing the essential Mg2+ ions. PMSF in a concentration of 1 mM does not inhibit the endonuclease.

Questions and Answers:

Question: Is the endonuclease activity of Dr. Nuclease similar to MilliporeSigma Benzonase nuclease?
Answer: Yes. The same gene is used for the enzyme expression. High standard quality control is performed to guarantee high enzymatic activity.

Question: Compared to the price of Merck Benzonase nuclease, that of Dr. Nuclease is very low. Do you provide free sample of Dr. Nuclease?
Answer: Actually the price of Dr. Nuclease is the lowest among Merck Benzonase nuclease alternatives. Sorry that we do not provide free sample. Clients can place an order and we will hold the invoice until they tell us that they like our product. Clients do not need to pay us if they do not like the product. It is an alternative to free sample. We also have a promotion for the 100 kU: $100 for the first time buyer.

Question: We need low-endotoxin or even endotoxin free endonucleases for AAV purification since our purified AAV is used for animal injection. What is the endotoxin level of Dr. Nuclease?
Answer: The endotoxin level is ≤0.5 EU/1000 units for research grade Dr. nuclease, and ≤0.01 EU/1000 units for GMP grade Dr. nuclease.

Question: Do you provide GMP grade Dr. Nuclease?
Answer: We have sold RUO grade Dr. Nuclease for research use only for years. Our clients told us that the cost of the GMP grade nuclease enzyme is a major cost of viral vector manufactuing. To help clients reduce the cost, we introduced the GMP grade Dr. Nuclease to the market in 2023. Again, our GMP grade nuclease is the cheapest Benzonase nuclease alternative.

Question: Will the price of your GMP grade Dr. Nuclease be much higher than the RUO grade enzyme?
Answer: The price difference is not significant.