Unit substrate: Lambda DNA.

Unit calculation assay conditions: 50 mM NaCl, 10 Tris-HCl (pH 7.9 @ 25°C), 10 mM MgCl₂, 1 mM dithiothreitol, 100 μg/ml BSA. Incubate at 37°C.

Absence of contaminants: 400 units of Rsa I do not produce any unspecific cleavage products after 16 hrs incubation with 1 μg of λ DNA at 37^oC.  After 10-fold overdigestion with Rsa I, greater than 95% of the DNA fragments can be ligated and recut with this enzyme.

Storage buffer: 50 mM KCl, 10 mM Tris-HCl (pH 7.4), 0.1 mM EDTA, 1 mM dithiothreitol, 200 μg/ml BSA and 50% glycerol. Store at -20^oC.

Heat inactivation: 65^oC for 20 minutes.

Methylation Sensitivity:

dam methylation: Not sensitive

dcm methylation: Not sensitive

CpG methylation: Blocked by some combinations of overlapping

Note: Cleaves single-stranded DNA slowly.

Reagents supplied: 10x M and 10x K buffer