thank you Amira I will read more about this.

Could you not just precipitate your sample with TCA (10% final), Acetone, etc resuspend the pellet it 1X Laemmli buffer, (neutralize with 1 M Tris base if TCA was used), heat, and run the samples?

Dear Bruce,

using TCA seems very sensible, I will definitely try it. Thank you very much for your help.

Maybe you could test also Zebaspin Columns for desalting. Another Option are Amicons Ultra Devices, which are available with different cut-Offs. But depending on the origin of your sample and the exact content, the desalting step could take long using this devices. What is the origin and volume of you samples?

 Dear Annika,

Thank you for your answer, I'm using bacterial lysate and indeed I used the Amicons Ultra devices and they were no good!

I made the same experience with my samples. For my application (simple reduction of salt Content) the Zebaspin columns work well. If you have a high sample throughput and low sample volumes you could also use the 96-well Formate of the Zebaspins.

Or G25 spin columns that GE Healthcare sells