Hi!
I have a protein product containing 10% glycerol. Do I need to dialyse to rid off the glycerol first and then add 9 volumes of absolute ethanol, or can I directly add 9 volumes of ethanol?
Thank you!
Best Regards,
Zonghan
If you add ethanol, you will precipitate (and hence denature) the protein. It may not be functional anymore.
Hello Zonghan, I think more information and context will help folks provide suggestions. What exactly is your goal? Are you trying to purify a recombinant protein, extracting total protein from comestibles, etc.? If you are purifying a recombinant protein then I agree with Libor, you will end up denaturing your sample. Once folks know your goal, we can provide more useful feedback. Thanks!
Since glycerol increases protein solubility that can hinder precipitation, you can directly add 9 volumes of absolute ethanol, but keep in consideratio that the efficiency of protein precipitation might be affected in the presence of 10% glycerol . So you have another option ; to do dialysis before ethanol precipitation (recommended for maximum yield) .
Best approach:
- if maximum protein recovery is critical : dialysis first then ethanol.
- If convinienc is more important and some loss is acceptable: direct ethanol addition (90%) and chilling should work.
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