Supplied in:

10 mM Tris-HCl (pH 7.4); 50 mM NaCl; 0,1 mM EDTA; 200 µg/ml BSA; 1 mM  DTT; 50% glycerol.

Reaction Conditions:

1XSEBuffer B.

Incubate at 37°C.

1XSEBuffer B 

10 mM Tris-HCl (pH 7.6 @ 25ºC), 10 mM MgCl2, 1 mM DTT

Unit Definition:

One unit is defined as the amount of enzyme required to digest 1 µg of  λ DNA in 1 hour at 37°C in a total reaction volume of 50 µl.                    

Quality Control Assays

Ligation:

After 10-fold overdigestion with Zra I, approximately  90% of λ DNA fragments can be ligated with T4 DNA Ligase and recut.  In the presence of 10% PEG ligation is better.

16-Hour Incubation:

A 50 µl reaction containing 1 µg of λ DNA and 10 units of enzyme incubated for 16 hours resulted in the same pattern of DNA bands as a reaction incubated for 1 hour.

Oligonucleotide Assay:

No detectable degradation of a single- and double-stranded oligonucleotide was observed after incubation with 10 units of enzyme for 3 hours.

Enzyme Properties

Activity in SEBuffers:

SEBuffer B    100%

SEBuffer G    50-75%

SEBuffer O    25-50%

SEBuffer W   25-50%

SEBuffer Y    75-100%

SEBuffer ROSE  100%

When using a buffer other than the optimal (suppied) SEBuffer, it may be necessary to add more enzyme to achieve complete digestion.

Zra I is a neoschizomer of Aat II.

Heat Inactivation:

Yes   (80°C for 20 minutes)

Reagents supplied with enzyme:

10XSEBuffer B

Notes:

High enzyme concentration may result in star activity. The minimum number of units that resulted in complete digestion of 1 ug of substrate DNA in 16 hours is 0,5. Zra I cleaves linear plasmid DNA at a rate 1,5-2 times higher than supercoiled plasmid DNA.