Unit Definition

One unit is defined as the amount of enzyme required to protect 1 μg λ DNA in 1 hour at 37°C in a total reaction volume of 10 μl against cleavage by EcoRI restriction endonuclease

Reaction Conditions

1X rCutSmart™ Buffer
Supplement with 80 µM S-adenosylmethionine (SAM)
Incubate at 37°C

1X rCutSmart™ Buffer
50 mM Potassium Acetate
20 mM Tris-acetate
10 mM Magnesium Acetate
100 µg/ml Recombinant Albumin
(pH 7.9 @ 25°C)

Control Protection Assay

rCutSmart Buffer is incubated with 1 µg of λ DNA in 10 µl 1X EcoRI Methyltransferase Buffer, supplemented with 80 µM S-adenosylmethionine, for one hour at 37°C followed by 15 minutes at 65°C. The extent of protection by EcoRI Methyltransferase is determined by the addition of 40 µl rCutSmart Buffer supplemented with 10 mM MgCl₂ and 5 units of EcoRI restriction endonuclease. Incubation at 37°C for 30 minutes is followed by analysis on an agarose gel.

Storage Buffer

100 mM KPO₄
200 mM NaCl
10 mM β-ME
0.1 mM EDTA
200 µg/ml BSA
50% Glycerol
pH 7.4 @ 25°C

Heat Inactivation

65°C for 20 minutes

Molecular Weight

Theoretical: 37911 daltons