The choice of precioitation technique depends on your protein. Run the one that allows you redissolving most of the precipitate. If you go this way you need to wash the precipitate to help removing sds. The sds extraction process could be long depending again on your protein. 

I will rather use dialysis or diafiltration to remove sds.

Hi Gerry,

The detergent removing kits are not as effective as precipitation methods.  I find the TCA precipitation in presence of deoxycholate (DOC) to be the best method.

Acetone precipitation also is a very good one.  I would run the protein solution before and after removal of SDS to make sure the recovery of the protein is acceptable.  You can practice with a standard protein solution that has the same concentration as your sample and once you are happy about the procedure, apply the steps to your protein solution in SDS.

I have attached a publication that describes acetone precipitation.

Good luck.

Hediye.

Thanks Hediye

TCA sounds good. Do you think it is as effective as ammonium acetate ? Although acetone precipitates larger volumes of protein  I always suspected that it may be rather a harsh solvent for protein mixtures. Really interesting paper also for some other topics i am researching thanks.

Apart from the Bensadoun & Weinstein technique (TCA + DOC)

@ARTICLE{Ben-76,

title = {Assay of proteins in the presence of interfering materials},

author = {A. Bensadoun and D. Weinstein},

journal = {Anal. Biochem.},

year = {1976},

pages = {241-250},

volume = {70},

doi = {10.1016/S0003-2697(76)80064-4},

language = {eng},

}

you could also try the chloroform/methanol technique of Wessel & Flügge. In my hands at least recovery is higher:

@ARTICLE{Wes-84,

title = {A Method for the quantitative recovery of protein in the presence of detergents and lipids},

author = {D. Wessel and U.I. Flügge},

journal = {Anal. Biochem.},

year = {1984},

pages = {141-143},

volume = {138},

doi = {10.1016/0003-2697(84)90782-6},

language = {eng},

}

Biobeads SM2 or Amberlite XAD can gently remove detergents, in the presence of phospholipids proteins are reconstituted into liposomes:

@ARTICLE{Rig-02,

title = {Membrane proteins: functional and structural studies using reconstituted proteoliposomes and 2-{D} crystals},

author = {J.L. Rigaud},

journal = {Braz. J. Med. Biol. Res.},

year = {2002},

pages = {753-766},

volume = {35},

doi = {10.1590/S0100-879X2002000700001},

language = {eng},

url = {http://www.scielo.br/pdf/bjmbr/v35n7/4512.pdf},

}

Thanks Engelbert . I have tried TCA and methanol but not DOC, I will add this. Methanol/chloroform is currently my preferred choice because of quantity as you suggest . I have used Amberlite XAD16 before but not for SDS removal , this is a good suggestion . I will also take a look at the biobeads , I have not heard of them before but it sounds like a useful tool !

TCA or acetone precipitation works great. You cannot remove SDS by dialysis effectively since it is hard for the detergent to traverse the membrane. Good luck with the DOC method- I have not tried that one but it should work.