关于DNase1的相关问题

yuanyan2010

有哪位朋友可以告诉一下DNase1粉末状的一般用什么来溶解？还有他的浓度和u/mg有关系吗。例如Deoxyribonuclease I from bovine pancreas
) z: ~+ n' V3 j* @# F$ RType IV, lyophilized powder, ≥2,000 Kunitz units/mg protein  ;总量是15KU
) k0 P* W$ }' ] ;想配成300 mg/ ml DNase I。要怎么换算。。。谢谢啦

yuanyan2010

没人理我啊。。。。

细胞海洋

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6 K* Y. @+ H: I3 v+ e: I- i1 Z& ]回复 yuanyan2010 的帖子
9 h, ~) J+ ^/ \' m1 H* g  G8 B9 @/ @* j+ F" Y' S( V( c) m, ~
再耐心等一下

ziyunfei1982

不同厂家的DNaseI mg与单位数换算是不一样的，因为DNaseI 的效价也就是活性不一样，所以很难确定。你那个是从胰腺组织中提取的，这是老外的原话，It hard to convert units to weight unless the vendor provides such information. Some vendors say one mg dry weigt of DNase I has >2,000 Kunitz units. Qiagen explicitily says that one mg = 2500 Kunitz units. If this is given, you can estimate the weight. However this number may not be applied to DNase from another vendor since they may have different activity.
  f& }+ n1 y2 k  F我们在降解RNA中的DNA用量一般一个unit足够，做DNaseI hypersensitive sites时就得精确计算了，因为不同的DNaseI浓度和buffer对染色质的切割方式是不同的另外，此酶的活性和切割方式严重依赖2价阳离子以及反应温度。1 Z, e+ q3 w4 y8 Q$ Z( H  Z: a; ?
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ziyunfei1982

One Kunitz unit is defined as the amount of DNase I that causes an increase in A260 of 0.001 per minute per milliliter at 25°C, pH 5.0, with highly polymerized DNA as the substrate
  g: V$ w' z' C  W% J; ^+ o3 VOne unit is the amount of the enzyme required to degrade 1 mg of calf thymus DNA in 10 minutes at 37°C completely. (1.5 units = 1 Kunitz unit)7 J& @! o' C" h. o# x4 n