(Thermus aquaticus)
5’-T C G A-3’
3’-A G C T-5’
Reaction Temperature: 65°C
Prototype: TaqI
Inactivation Temperature (20 min): --
Reaction Buffer:
1x High Buffer: 50 mM Tris-HCI (pH 7.5 at 37°C), 10 mM MgCl2, 100 mM NaCl, 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 Ф X174 RF1 DNA in 1 hr in a total reaction volume of 50 µl.
Assay Conditions: 50 mM Tris-HCl (pH 7.5 at 37°C), 100 mM NaCl, 10 mM MgCl2, 1 mM dithiothreitol, 100 µg/ml bovine serum albumin and 1 µg of Ф X174 RF1 DNA. Incubation is at 65°C for 1 hr in a reaction volume of 50 µl.
Storage Buffer: 20 mM potassium phosphate (pH 7.0), 100 mM NaCl, 0.1 mM EDTA, 1 mM dithiothreitol, 0.02% Triton™X-100, 200 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 TaqI with 1 µg of unmethylated lambda DNA at 65°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 TaqI and 0.25 µg of 3'-ends of lambda/TaqI fragments (3'-labeled with T4 DNA Polymerase and [³H]dGTP and [³H]dCTP), incubated for 1 hr at 65°C resulted in 0.02 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 TaqI with 0.05 µg of 5'-ends [5'-³²P]lambda/HaeIII fragments for 1 hr at 65°C resulted in 0.02 slope of %-end label released per unit of enzyme. Reaction volume 10 µl.