## Nuclear protein purification

**Moderator:** BioTeam

- bravebeaker
- Garter
**Posts:**44**Joined:**Sun May 08, 2011 3:26 am**Location:**Kobe, Japan

### Nuclear protein purification

Hi all,

During nuclear protein purification I came across the step where I need to add 5M NaCl slowly with shaking until I adjust the molarity to 2M NaCl, how many mls do I need to add?

Honestly I tried to tackle the problem in different ways but I couldnt, any help would be really appreciated.

Thanks all.

During nuclear protein purification I came across the step where I need to add 5M NaCl slowly with shaking until I adjust the molarity to 2M NaCl, how many mls do I need to add?

Honestly I tried to tackle the problem in different ways but I couldnt, any help would be really appreciated.

Thanks all.

AHH, Gravity! Such a cold cruel mistress.

- bravebeaker
- Garter
**Posts:**44**Joined:**Sun May 08, 2011 3:26 am**Location:**Kobe, Japan

Thank you for the elaboration, I know its been almost a month for me to reply I am sorry for that but I finally tried the experiment and the volume I am adding to is 5 ml. But I am not sure how we reached the 2/3 ratio of the original volume.

because 2/3 = .66 and if we multiply (.66)(5ml) I will get 3.3ml to add which is correct but still I dont understand why.

because 2/3 = .66 and if we multiply (.66)(5ml) I will get 3.3ml to add which is correct but still I dont understand why.

AHH, Gravity! Such a cold cruel mistress.

cV = cV right? So, you'll have:

2M . V1 = 5M . V2

2M/5M = V2/V1 -> ratio of original (5M stock) and final (your solution) volumes is 2 : 5. In other words, the 5M solution will make 2 parts of of 5 parts of 2M solution. Thus the solution to which you're adding the NaCl will make 3 parts of it, thus 2/3.

2M . V1 = 5M . V2

2M/5M = V2/V1 -> ratio of original (5M stock) and final (your solution) volumes is 2 : 5. In other words, the 5M solution will make 2 parts of of 5 parts of 2M solution. Thus the solution to which you're adding the NaCl will make 3 parts of it, thus 2/3.

http://www.biolib.cz/en/main/

*Cis*or*trans*? That's what matters.- bravebeaker
- Garter
**Posts:**44**Joined:**Sun May 08, 2011 3:26 am**Location:**Kobe, Japan

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