Bradford quantitatn problem - precipitation - protein lysate precipitate when added to assay reagent (Nov/13/2009 )

Hi,

I extracted my protein using 2%SDS (scraping, sonication). It precipitate out as blue particle when i added into my bio-rad protein assay reagent. It made quatitation impossible. I never encounter it when i use RIPA..

I tried to dilute it out. precipitate still occur but in lesser extent.

Any help would be greatly appreciated!

Thanks

i ve observed this wen using bradford reagent with SDS.. try diluting with GuHCl it will solubilize the protein better
best luck!!!