Assessment of dialysis - How?

[stony]

In the work of purifying a protein, my last step is dialyse it. but i dont know how to assess the result of that dialysis procedure? how can we know that the salt is removed from our sample partly or completely?
pls, i'm a little urgent about this. thanks!

[mith]

salt as in Nacl? If so you can try testing it by using silver nitrate.

[stony]

not only NaCl, I got immidazole, and another case, got salts in PBS ... so only silver nitrate can't help!
any other way?

[MrMistery]

I'm not sure there is a way. either than making a list of every salt you need to test for and using specific reagents for each of them(eg: silver nitrate for NaCl)

[mith]

maybe evaporating the sample to see if there's any salt residue.

[Daniel Tillett]

You could try using a DNA electroporator unit. I did this once to measure low levels of salt in a sample. Just make up a standard curve using a known concentration of salt and compare the time constants between your sample and the known standard. Just don't use too high a concentration of salt

Daniel

DNA sequencing analysis software

[stony]

thanks for ur all help. I just can't make so many assays because my sample is limited and the DNA electroporator unit as Daniel Tillett has told is not available in my lab. Evaporating may harm my protein, too. hic, may be i'll try if the Nanodrop machine in my lab can show the peak of salts and make a comparison bt the sample before and after dialysis.
thanks a lot again!