Remove albumin from purified protein sample? Help please - (Sep/19/2007 )

Hello experts,

I have purified some protein using affinity column. However, we always get about 20% albumin contamination always, despite good washes.

Can anyone recommend a simple way to remove albumin from my sample?

I am already trying ammonium sulfate precipitation. However, my protein is 50 kDa and albumin is about 65kDa. Don't know if ammo.sulfate will help. My gel will tell today.

Any other tested methods?

thanks a lot.

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what is the source of such high conc of albumine? are you working with blood plasm/serum?

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HUMAN SEMINAL PLASMA

I prefer not to fractionate it first, as my next step is affinity purification and I know that my protein is not very stable to be able to sustain the stages of fractionation before binding to the affinity column.

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There are some dye affinity column for albumin binding. Check with GE or sigma.

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I found it in Bioforum topic Remove BSA from cell culture medium BSA removal

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the dye binding methods of albumin removal tend to bind other proteins, as well. you would need to confirm that the dye does not bind a significant amount of your protein with the conditions used for albumin binding.

alternatively, beckman-coulter offers a IgY based method of albumin removal which should be very specific (since it is from b-c i would expect it to be expensive, but i could be wrong).

as for ammonium sulfate: as works more by hydrophobicity than by size. it is possible that you can remove albumin with as fractionation. you just need to determine the proper steps.

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