A possible alternative are detergent removal columns (http://www.piercenet.com/browse.cfm?fldID=25F159A5-5056-8A76-4E63-399F97138252).

Alternatively I´d recommend to use Chloroform/Methanol (aka. Wessel-Fluegge) Precipiation (http://www.biologie.uni-konstanz.de/fritz/documents/Protein_precipitation-methods.htm).

Good luck!

Thanks Stefan and Rishikesh. I will try Chloroform/methanol precipitation.

I also used TCA/acetone (-20°C) for precipitation (and removing salts in general).

I don't know your instrumentation for IEF, but when I was carrying out 2D electrophoresis, I used Protean IEF cell for IEF. Wet paper wicks you put on electrodes absorb SDS (and salts) from sample (first step of IEF should be at low voltage for some time, i.e. 200V for 2-3 hours maybe)

In addition SDS at low concentration (0,25%, but CHAPS or other detergent 8-times more) can increase the separation.

you may look: http://pcp.oxfordjournals.org/content/early/2009/10/30/pcp.pcp154.full.pdf

Thanks Jan, I'am using protean IEF, it works well with paper wicks when SDS concentration is lower tan 0,25%. I already tryed. Problems become when SDS concentration is higher. For this reason I have to remove it.

Other possible way to remove salts (and other contaminants, including SDS) is using microtubes with cut-off filters (I use Vivacon 500, 10.000 MWCO) and washing with 8M urea.

You only put your sample into microtube, add 200ul of urea and centrifuge 30 min in 14.000xG, you repeat it 6-8times, after last step you rehydrate sample directly in the microtube in your rehydration buffer. You would get rid of contaminants as well (all smaller than 10kDa) and It works pretty well too.

(last two steps I use 7M urea and 2M thiourea, instead of 8M urea)

Hi Maria, Acetone precipitation works really well for use with IEF. Ice cold acetone to a final concentration of 80%. Leave at -20 degrees C for 90 mins (no longer). Centrifuge at high speed for 15 mins and remove supernatant. Then air dry the protein pellet and resuspend in your IEF sample buffer. Good luck ! Brad

Hi Bradley, did you use it already to remove SDS. I think this is the faster method. what about protein yield?

Hi Maria, Yes we used it to remove SDS and salts too. Protein yield is good for IEF and 2D gels. Regards, Brad

how about the Bio-Rad Bio-Spin 6?(732-622)

Hi, Bradley, you are right, ice-cold acetone to a final concentration of 80% worked well! Thanks again, best regards, Maria Teresa

Hi,

I am using surfactant in sample preparation. Need to remove them before LC-MS analysis, and protein is not my target analytes. FASP has been recommended to remove surfactants, is just added urea and centrifuge the samples but is quit time consuming? 

Please help

Hi Alyah,

do you need a method to remove surfactant from your protein sample, isn't it?

I use Acetone/TCA precipitation, 2 volume of cold acetone/TCA20% (9/1), -20°C for at list 2h, then centrifugation 13-15000 rpm, 4°C, 20-30 min. I hope it will help you

good luck

Maria Teresa

Thanks Maria,

I need surfactants and proteins as am using surfactants for metabolite extraction.

Sorry, to remove both of them surfactants and proteins

Use potassium salt at low temperature. SDS will be precipitated. you cab go to this link.

Suzuki H, Terada T. Removal of dodecyl sulfate from protein solution. Anal Biochem. 1988;172:259-63

Article Removal of dodecyl sulfate from protein solution

I have a query (stupid, i guess)..is there a possibility of precipitation of SDS together with the protein, since the precipitation has to be done at a low temperature?