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?
On Mon, Apr 8, 2013 at 8:34 PM, DK <d...@no.email.thankstospam.net> wrote: > In article <mailman.236.1365452782.10461.meth...@net.bio.net>, Sudheer > Sangeetham <sudheer.pb...@gmail.com> wrote: > >Hello all > > > >I would like to quantify the protein concentration. I checked the nanodrop > >manual in that they have given that I can estimate the protein by > measuring > >directly at 280 nm by giving extinction coefficient value without doing > >bradford or lowry methods. I would like to choose measuring the protein > >concentration directly. Because I need to handle many samples all the > time, > >so it is difficult for me to do bradford or lowry methods all the time. So > >How far is correct if I estimate the protein concentration directly? > please > >give me your suggestion > > To expand on Nick's answer a bit: > > 1. If your protein is quite pure, A280 + theoretical extinction coefficient > given by Protparam will *usually* get you as close to the real > concentration > as almost anything else (quantitative amino acid analysis is still a golden > standatd but it's almost a lost art that few can execute competently and > reliably these days). > > 2. If your protein is not very pure - particularly if contaminated by > nucleic > acids or large amounts of small molecules that absorb UV strongly, then > just about anything else is going to be much more accurate than A280. > > DK > _______________________________________________ > Methods mailing list > Methods@net.bio.net > http://www.bio.net/biomail/listinfo/methods > _______________________________________________ Methods mailing list Methods@net.bio.net http://www.bio.net/biomail/listinfo/methods
