Folin-Wu Protein Precipitation method

[darkchoc]

hi!

I am doing an experiment on serum deproteinisation for a biochem subject, I am quite lost...
just wondering why the acid (H2SO4) must be added to the serum before the anionic precipitant (10% sodium tungstate)?

Also, for Cl- and K+ estimations, is it better to use serum or plasma?


THANKS A LOT!

[Dr.Stein]

The acid addition is because the precipitant works in acidic pH.

For estimation Cl- and K+, as far as I know, there is no problem to use whether serum or plasma since the different between them is only the presence of coagulation factors and they don't interefere with those ions very much.

[darkchoc]

thanks so much!!!



ive got a few more questions...

how do i find out what concentration of (NH4)2SO4 precipitates globulins and not albumin from a serum?

and

what component of a serum is affected by coprecipitation and adsorption? is it just the protein component?


THANKS A MILLION!!!

[Dr.Stein]

50% saturated (NH4)2SO4 in a very small amount (0.0005 to 0.001%)

If the context of precipitation used here is regarding immunological reaction, then it is all about protein

[darkchoc]

You're a life saver!

Thank you so much!