In article <[email protected]>, [email protected] says... > > In article <[email protected]>, Vladimir > Gainullin <[email protected]> wrote: > >Is it not true that after a standard curve is created (using a more > >accurate method) one can use the A280 to estimate protein concentration > >given that the sample is more or less similar? > > Yes. But the devil is in the "more or less similar" part. The samples tend > to have this unfirtunate habit of being different from what we think of them > :-) > > DK
Just to be fair, however, one should add that this is true for most methods in routine use. Lowry, Bradford, BCA...: they all have extinction coefficients that depend on amino acid composition of the protein(s) analysed. I did that with Hsc70 once: depending on method and standard protein used (BSA or IgG), the concentration determined varied by a factor of 20! There are lies, damn lies and protein concentrations. _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
