(Nocardia argentinensis)
 5’-G G C G C C-3’
 3’-C C G C G G-5’
 Reaction Temperature: 37°C
 Prototype: NarI
 Inactivation Temperature (20 min): 65°C
 Reaction Buffer:
 1x Low Buffer: 10 mM Tris-HCl (pH 7.5 at 22°C), 10 mM MgCl2, 1 mM dithiothreitol, 100 µg/ml bovine serum albumin.
 Unit Definition: One unit is the amount of enzyme required to completely digest 1 µg of Ad-2 DNA in 1 hr in a total reaction volume of 50 µl.
 Storage Buffer: 10 mM Tris-HCl (pH 7.8 at 22°C), 50 mM KCl, 1 mM dithiothreitol, 0.1 mM EDTA, 500 µg/ml bovine serum albumin and 50% (v/v) glycerol.
 Storage Conditions: Store at –20°C.
 Quality Control:
 Non-specific Endonuclease: Incubation of 10 units of NarI with 1 µg of Ad-2 DNA at 37°C for 16 hrs (a 160-fold over-digestion) resulted in the same sharp characteristic banding pattern as the standard assay reaction, as determined by agarose gel electrophoresis.
 3’-Exonuclease: 5, 10 and 20 units of NarI and 0.13 µg of lambda/TaqI fragments (3’-labeled with T4 DNA Polymerase and [³H]dGTP and [³H]dCTP), incubated for 1 hr at 37°C resulted in 0.25-slope of %-end label released per unit of enzyme. Reaction volume 10 µl.
 5’-Exonuclease/5’-Phosphatase: Incubation of 5, 10 and 20 units of NarI with 0.05 µg of [5’-³³P]lambda/HaeIII fragments for 1 hr at 37°C resulted in 0.18-slope of %-end label released per unit of