Function of BSA in pulse chase? - (May/18/2007 )

Hi,

Does anyone know what's the purpose of adding 0.1% BSA to the starvation and pulse media in a pulse chase experiment?

Jaakko

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may you offer some more details as there are numerous versions of pulse chaise experiments...?

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Hi,

I mean a standard pulse-chase for determining the stability of a protein in cultured mammalian cells:
-starvation in Met-free medium
-pulse labeling with [S³⁵]-Met
-chase with normal medium; cell collection and immunoprecipitation of the protein of interest at different time points

I have a protocol where starvation and pulse are done in Met-free DMEM + 0.1% BSA, and I'd just like to find out what's the function of BSA there.
I guess that it could be some kind of a carrier, but don't know for sure...

Jaakko

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one more question: are the cells non-attaching and suspended? if yes, BSA should avoid adhesion of cells to each other, and irregular labeling

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No, the protocol has been used for adherent cells. But of course the BSA addition might have been adopted from a protocol meant for suspension cells.
That's just the reason why I'm asking this. It's always nice to know why exactly you should do something you are told to do...

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