紧急求救：限制性核酸内切酶的说明看不懂
丁香园论坛
2007
我要开始做RFLP，需要买NEB的3种限制性核酸内切酶：RsaⅠ，DdeⅠ，BstUⅠ，但在NEB的网站上查到的这3种酶的说明却看不懂，因为不知道要买多少，所以也不敢买，急死我了！！！现在以RsaⅠ的说明为例，希望高手能解决我的燃眉之急，多谢了！！！
Rsa I
#R0167S 1,000 units $50 (USA)
#R0167L 5,000 units $200 (USA)
NEBuffer 1 2 3 4
% Activity 100 100 50 100
5´ ... G T^A C ... 3´
3´ ... C A^T G ... 5´
Source: An E. coli strain that carries the cloned Rsa I gene from Rhodopseudomonas sphaeroides (S. Kaplan).
Reaction Conditions: (Supplied with enzyme) NEBuffer 1
10 mM Bis Tris Propane-HCl, 10 mM MgCl2, 1 mM dithiothreitol (pH 7.0 @ 25°C). Incubate at 37°C.
Ligation and Recutting: After 10-fold overdigestion with Rsa I, > 95% of the DNA fragments can be ligated and recut.
Concentration: 10,000 units/ml. Assayed on lambda DNA.
Storage Conditions: 100 mM NaCl, 10 mM Tris-HCl (pH 7.4), 0.1 mM EDTA, 1 mM dithiothreitol, 200 礸/ml BSA, and 50% glycerol. Store at -20°C.
Diluent Compatibility: Diluent A
Heat Inactivation: 65°C for 20 minutes.
Note: Cleavage of mammalian genomic DNA is blocked by some combinations of overlapping CpG methylation.
我的问题主要有：
1.我在NEB网站上见到的总的说明说，1u的定义是刚好可以消化1微克的目标DNA，那么Ligation and Recutting：After 10-fold overdigestion with Rsa I中的10－fold的意思是不是说，如果我要消化2微克的DNA，必须要加20u的RsaⅠ？
2.Concentration: 10,000 units/ml中的浓度是什么意思？是说我买回来的酶的浓度是这么大吗？还是有别的含义？
3.Storage Conditions: 100 mM NaCl, 10 mM Tris-HCl (pH 7.4), 0.1 mM EDTA, 1 mM dithiothreitol, 200 礸/ml BSA, and 50% glycerol. Store at -20°C.中的存储条件里写了这么多试剂，是与RsaⅠ混在一起保存呢，还是有别的意思？
这几个问题都比较菜，可我就是无法解决，所以现在实验停顿下来，希望有好心人能耐心的帮我解决这个问题，多谢！！！！！！
Rsa I
#R0167S 1,000 units $50 (USA)
#R0167L 5,000 units $200 (USA)
NEBuffer 1 2 3 4
% Activity 100 100 50 100
5´ ... G T^A C ... 3´
3´ ... C A^T G ... 5´
Source: An E. coli strain that carries the cloned Rsa I gene from Rhodopseudomonas sphaeroides (S. Kaplan).
Reaction Conditions: (Supplied with enzyme) NEBuffer 1
10 mM Bis Tris Propane-HCl, 10 mM MgCl2, 1 mM dithiothreitol (pH 7.0 @ 25°C). Incubate at 37°C.
Ligation and Recutting: After 10-fold overdigestion with Rsa I, > 95% of the DNA fragments can be ligated and recut.
Concentration: 10,000 units/ml. Assayed on lambda DNA.
Storage Conditions: 100 mM NaCl, 10 mM Tris-HCl (pH 7.4), 0.1 mM EDTA, 1 mM dithiothreitol, 200 礸/ml BSA, and 50% glycerol. Store at -20°C.
Diluent Compatibility: Diluent A
Heat Inactivation: 65°C for 20 minutes.
Note: Cleavage of mammalian genomic DNA is blocked by some combinations of overlapping CpG methylation.
我的问题主要有：
1.我在NEB网站上见到的总的说明说，1u的定义是刚好可以消化1微克的目标DNA，那么Ligation and Recutting：After 10-fold overdigestion with Rsa I中的10－fold的意思是不是说，如果我要消化2微克的DNA，必须要加20u的RsaⅠ？
2.Concentration: 10,000 units/ml中的浓度是什么意思？是说我买回来的酶的浓度是这么大吗？还是有别的含义？
3.Storage Conditions: 100 mM NaCl, 10 mM Tris-HCl (pH 7.4), 0.1 mM EDTA, 1 mM dithiothreitol, 200 礸/ml BSA, and 50% glycerol. Store at -20°C.中的存储条件里写了这么多试剂，是与RsaⅠ混在一起保存呢，还是有别的意思？
这几个问题都比较菜，可我就是无法解决，所以现在实验停顿下来，希望有好心人能耐心的帮我解决这个问题，多谢！！！！！！
