Total volume 50...200 µL:
Incubate 1...2 hours at 37°C.
SAM-free buffer can be prepared as 10x stock and stored at -20°C. In our hands, incubation in NEBuffer 2 did not deliver complete methylation. SAM stock solution (200x) must be stored separately.
S-adenosylmethionine (SAM) must be stored at –20°C as 32 mM solution in 5 µM sulfuric acid and 10% ethanol. SAM in this solution stored under ideal conditions remains active for up to 6 months. SAM is unstable at (pH 7.5), 37°C, and should be replenished for reactions incubated longer than 2 hours. Always use freshly defreezed SAM. Aliquot (5...10µl) SAM upon delivery, freeze, and discard after defreezing.
New England Biolabs [NEB]