Nuclease, Serratia marcescens

Product Information
An endonuclease from Serratia marcescens that can completely digest all forms of DNA and RNA (including single-stranded, double-stranded, linear and circular) into 5'monophosphate oligonucleotides of 3-5 bases in length. It has no protein activity and is highly specific. It is expressed in a yeast system and is suitable for the removal of nucleic acids in various proteins and biological products. The reaction conditions are mild, the reaction time is short, and the nucleic acid removal efficiency is high.
The storage solution is: 20 mM Tris-HCl pH 8.0, 2 mM MgCl₂, 20 mM NaCl, 50% glycerol

Instructions
1. Sample preparation
1) Adherent cells: remove the culture medium, wash the cells with PBS, and remove the supernatant.
2) Suspended cells: collect the cells by centrifugation, wash the cells with PBS, centrifuge at 6,000 rpm for 10 min, and collect the precipitate.
3) Escherichia coli: collect the bacteria by centrifugation, wash once with PBS, centrifuge at 8,000 rpm for 5 min, and collect the precipitate.
2. Sample processing
The collected cell pellets are lysed at a ratio of mass (g) to volume (mL) of 1:10~20. Cells can also be lysed mechanically or chemically on ice or at room temperature (1 g of cells is approximately 10⁹).
3. Enzyme addition
1) Add an appropriate amount of MgCl₂ to adjust the Mg²⁺ concentration in the reaction system to within the range of 1-5 mM, and adjust the pH to 8-9.
2) Add enzymes at a ratio of 250 U to digest 1 g of cell pellets, and incubate at 37°C for more than 30 minutes. You can also select the addition scheme according to the recommended usage in the table above, increase the enzyme amount within a certain range, and the digestion time will be reduced accordingly.
Note: Enzyme activity is affected by factors such as ion concentration, reaction temperature and pH. It is recommended to explore the optimal concentration for the first use.
4. Supernatant acquisition
Centrifuge at 12,000 rpm for 30 minutes to obtain the cell lysate supernatant, and then conduct subsequent related experiments.
Note: If the solution is a high-salt solution, slightly acidic or alkaline, and contains a higher concentration of detergent or denaturant, the amount of enzyme should be appropriately increased or the incubation time should be extended.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.