EcoRI is a restriction enzyme purified from E. coli RY 13.

Unit substrate: Lambda DNA.

Unit calculation assay conditions: 50 mM NaCl, 100 mM Tris-HCl (pH 7.4 @ 25^oC), 5 mM MgCl₂, 0.025% Triton X-100, 100 μg/ml bovine serum albumin and DNA. Incubate at 37^oC.

Absence of contaminants: 100 units of EcoR I do not produce any unspecific cleavage products after 16 hrs incubation with 1 μg of Lambda DNA at 37^oC. After 50-fold overdigestion with EcoR I greater than 98% of the DNA fragments can be ligated and recut with this enzyme.

Storage buffer: 300 mM NaCl, 5 mM KPO₄, (pH 7.4), 0.1 mM EDTA, 1 mM dithiothreitol, 0.15% Triton X-100, 200 μg/ml bovine serum albumin 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: Impaired by overlapping

Star activity: Conditions of low ionic strength, high enzyme concentration, glycerol concentration>5%, or pH>8.0 may result in star activity.