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Source
: Staphylococcus warneri
Compatible ends
: with any blunt end
Isoschizomers
: Smi I
Methylation Sensitivity
: Not sensitive to dcm, dam and CpG methylation
Unit definition :
One Unit is defined as the amount of Swa I required to completely digest 1 ㎍ of Ad-2 DNA in one hour at 25℃ in 50 ㎕ assay mixture.
Typical Reaction Conditions
: Add 5 ㎕ of 10X Reaction Buffer 'Swa I'[final conc.: 50 mM Tris-HCl (pH 7.9 @ 25℃), 10 mM MgCl2, 100 mM NaCl, 1 mM DTT], 1~2 ㎕ of DNA(0.5~1.0 ㎍/㎕), 5 ㎕ of 10X BSA(final conc.: 100 ㎍/㎖), 1 ㎕ of Swa I and 37~38 ㎕ of sterile water in 50 ㎕ reaction mixture. Incubate at 25℃.
Heat Inactivation
: 65℃ for 20 min.
Activity in BeamsBio™ Buffer System
|
Rxn Buffer |
A |
B |
C |
D |
'Swa I' |
|
Activity(%) |
<10 |
<10 |
50~75 |
75~100 |
75~100 |
|
Activity in a complete PCR Mix : less than 10%
Conditions: [10 mM Tris-HCl(pH 8.3 @ 25 ℃), 50 mM KCl, 1.5 mM MgCl2, 2 pmol of primers, 200 μM dNTP Mix, 2.5 U Taq DNA polymerase and 1 ㎍ of DNA(template or substrate) in 50 ㎕ of reaction volume] After 30 amplication cycles, add 5 units of Swa I. And then incubate at 25℃ for one hour. Relative activity is determined by gel electrophoresis.
Storage Conditions
: 10 mM Tris-HCl (pH 7.4 @ 25℃), 400 mM NaCl, 0.1 mM EDTA, 1 mM DTT, 200 ㎍/㎖ BSA, and 50% glycerol. Store at -20℃.
No. of Cleavage Sites
|
λ
|
Ad2
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pUC18
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φX174
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pBR322
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M13mp18
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SV40
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0
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1
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0
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0
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0
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1
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1
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Quality control
Overdigestion: The same band pattern as a digestion in one unit of Swa I for one hour was showing after incubation of 1 ㎍ of Ad-2 DNA with units of Swa I for 16 hr in 50 ㎕ of reaction mixture at 25℃ as determined by agarose gel electrophoresis.
Ligation-Recut: After a 10-fold digestion for one hour, % of Ad-2 DNA fragments were ligated with T4 DNA ligase at 16℃ and % of the ligated fragments could be recut with Swa I.
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Notes
- Conditions of low ionic strength, high enzyme concentration, glycerol > 5%, or pH > 8.0 may result in star activity.
- Swa I is very unstable at 37°C(50% activiy). The reaction temperature for Swa I is 25°C.
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References
Lechner, M., Frey, B., Laue, F., Anton-Botella, J., Smith, C.L., Ankenbauer, W., Schmitz, G.G. Nucleic Acids Res. 20: 2293-2296 (1992)
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