secreted proteins purification - how to concentrate a secreted protein contained in conditioned medium? (Aug/21/2007 )

Hello!!!

I would like to now what is the better method to concentrate secreted proteins, after washing the cells and adding serum free media.

Many thanks.

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it depends on how pure you want your protein to be,

if purity is not such an issue you could use centrifiugal concentrators (microcon) you can choose from various size cut offs.

if you want it really pure you may want to run it down a column (MonoS/Q) or do some gel filtration

hope this helps

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in addition to jimmy september, concentrating by speedvac and subsequent dialysis; various methods may be combined

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Ammonium sulphate precipitation is often a good way to concentrate and fractionate at the same time. Tangential flow filtration will get 1l of culture supernatant down to under 100 ml in a day, and you can also combine diafiltration to change the buffer for your next stage.

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thanks!!! by the moment I don`t need a high purity. I just need to be able to detect my protein in the media.

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