SspI is a restriction enzyme purified from Sphaerotilusspecies.
Reagents supplied: 10x R3 and 10x EQ buffer
Unit definition: One unit is the amount of enzyme required to digest 1 μg of Lambda DNA in 60 min at 37oC in a total reaction volume of 50 μl.
Digest Guidelines
Standard reaction conditions: In order to overcome DNA source variability, a ~10 fold overdigest is suggested:
10U Ssp I
1μl
10x EQ buffer
5μl
DNA substrate
1μg
Sterile ultrapure water
Up to 50 μl
Speed Digest reaction: Incubate for 15 minutes at 37oC as in standard reaction in 1x R3 buffer (100 mM NaCl, 50 mM Tris-HCl (pH 7.9 @ 25°C), 10 mM MgCl2, 100 μg/ml BSA) or 1x eQ buffer (20 mM Tris-acetate (pH 7.9 @ 25oC), 10 mM Mg-acetate, 50 mM K-acetate, 100 μg/ml BSA).
Activity(%) in EnzyQuest buffers-Double digest tips
R1
R2
R3
R4
EQ
10-25
75
100
50
100
Reactions were performed as for unit definition reaction. The above data could be used as guideline for double digest reactions. Our enzymes are also active and compatible in buffer systems from other vendors.
Heat inactivation: 65oC for 20 minutes
Methylation Sensitivity:
dam methylation: Not sensitive
dcm methylation: Not sensitive
CpG methylation: Not sensitive
Unit calculation assay conditions:
1x R3 buffer
Lambda DNA
Incubation at 37oC
Storage conditions:
50 mM KCl
10 mM Tris-HCl (pH 8)
0.1 mM EDTA
1 mM dithiothreitol
200 μg/ml BSA
50% glycerol
Store at -20oC
Non-specific nuclease activity: 30 units of Ssp I do not produce any unspecific cleavage products after 16 hrs incubation with 1 μg of Lambda DNA at 37°C.
Re-ligation and recut: After 10-fold overdigestion with Ssp I, greater than 95% of the DNA fragments can be ligated and recut with this enzyme.
Star activity: Conditions of low ionic strength, high enzyme concentration, glycerol concentration >5%, or pH >8.0 may result in star activity.