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 % y& U- V$ F% E: [
Type IV, lyophilized powder, ≥2,000 Kunitz units/mg protein ;总量是15KU5 k& I+ h2 k- h1 N
;想配成300 mg/ ml DNase I。要怎么换算。。。谢谢啦
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. & b7 ?4 k1 X" b4 c |+ ?. |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。 5 Z+ M( i. ?, z% I& @1 B& o# l9 I/ K( o+ g5 v: x
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 " |: |% s+ T( d& }5 pOne 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) 9 ~2 X- p! O, d; k/ O; S, Z
发表于 2012-3-21 19:01
发表于 2012-3-27 01:10
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