Separation of protein size of 20kDa and 150kDa - (Jul/03/2007 )

Hi everyone,

Is it possible to separate two proteins with the size of 20kDa and 150kDa? I heard that the cut off should be about 2 times smaller than the protein size, is that true? Is such memebrane comemercially available?

Many thanks!

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in general, the separation by membrane filtration is not to recommend; however, the question is what enrichment or purity do you need; if you need some enrichment over the other, you may try; better results are by gel filtration...

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Dialysis?

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you could use ultracentrifugation filter devices (e.g. Amicon from Millipore, or Vivaspin from Vivascience) with an adequate MWCO. e.g. 50kD, 80kD or 100kD then the 20kD is in the flow through and the 120kD is in the retentate (concentrate).

hope that this is useful for you, or you could think about that.

http://www.millipore.com
http://www.sartorius-stedim.com/index.php?id=2768

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Hi guys,

Thanks a lot for your response

i've thought about using the ultra centrifucation filtration, but the problem is that i have lots of samples to investigate. therefore i need a high throughtput filtration (for 96-well microplate).

thanks & regards,
poon

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