Chromatography Forum

Hi,
I have one unknown protein of molecular weight 31 kDa. pI 8.2, stable at around pH 4- pH 10, expressed in soluble fraction at 10-12 mg per liter of original culture.
Thats all i have?
on the basis of molecular weight i think so i cant go for molecular sieve chromatography. But as it has pI of 8.2 and stable in acidic pH, I think so i should go for cation exchange chromatography.

Am i going rite?
and what does the last part mean, expressed in soluble fraction at 10-12 mg per liter of original culture - --------> can we determine any technique from this information or its just for column capacity selection. If yes what should be the column capacity.

Let me back up a step and ask what you are trying to do? Are you trying to purify - and if so, from what? Are you trying to verify purity? Or are you trying to do something else?

Its just theoretical project, it does not involve any wet lab experiment.
My tutor gave me one question which say protein molecular weight, pH and soluble fraction. Using this information i have to select a chromatography technique to purify that protein.

Can u please help me

I suspect that you will learn best if you research this yourself and come up with your own answer. Look in your books, notes from instruction, and then use published papers. You will then learn - which is what having a tutor is all about.

In my question i told the answer, i just want to know am i going on right track

answer
on the basis of molecular weight i think so i cant go for molecular sieve chromatography. But as it has pI of 8.2 and stable in acidic pH, I think so i should go for cation exchange chromatography.