Frequently Asked Questions about DENARASE^® & DENARASE^® High Salt

DENARASE^® High Salt is an engineered version of the standard DENARASE^® endonuclease. Compared to the wild-type enzyme, a few amino acids were substituted to make the enzyme more tolerant to higher salt conditions, without affecting its specificity for nucleic acids.

No, the activity of the wild-type DENARASE^® is unbeatable at lower salt concentrations and for this reason the standard DENARASE^® endonuclease will be available for such applications.

As a rule of thumb, we recommend DENARASE^® High Salt for processes with salt concentrations above 200 mM. For applications below 200 mM salt the standard DENARASE^® is more suitable. However, conditions such as pH and the magnesium concentration also impact the activity of both enzymes. For this reason, we recommend testing for the best enzyme in applications with salt concentrations ranging from 150 to 250 mM. Please contact one of our specialists for more details on the optimal conditions for both enzymes.

There are several publications on how to use endonucleases derived from Serratia marcescens, such as DENARASE^®. We recommend starting with concentrations between 10 and 60 U/mL. Several parameters such as time, concentration and temperature are highly dependent on your process conditions and should be evaluated accordingly.

A variety of methods are available to remove DENARASE^® and DENARASE^® High Salt from target products. Depending on the characteristics of the process, anion exchange, cation exchange, hydrophobic interaction, hydroxyapatite or size exclusion can be applied. Alternatively, filtration techniques can be used for specific process solutions. Depending on the target molecule, the type of chromatography or filtration media must be tested for the specific case.

Both DENARASE^® and DENARASE^® High Salt will be available in two different quality grades, a Research and Development and a GMP-grade. From a technical perspective both quality grades are equal and the specification parameters are the same. 

DENARASE^® and DENARASE^® High Salt are both derived from the Serratia marcescens endonuclease and differ only in a few amino acids. Therefore, both enzymes can be detected using the same commercially available Serratia marcescens endonuclease ELISA Kits such as our DENARASE^® ELISA Kit.

There are several agents that can inhibit DENARASE^® and DENERASE^® High Salt. Whereas approximately 600 mM NaCl are sufficient to inhibit the standard DENARASE^®, NaCl concentrations above 1 M are required to inactivate DENARASE^® High Salt. Depending on the used buffer, also potassium phosphate (200-300 mM) can be used to quench activity of both enzymes. Moreover, addition of chelating agents like EDTA (>5 mM), resulting in the loss of free Mg²⁺ ions, will inhibit the enzymatic reaction.

Yes, all batches for DENARASE^® and DENARASE^® High Salt must fulfill the specification set for endotoxin content (<0.25 EU/kU) prior product release. See also the DENARASE^® Validation Guide for more details.