In article <gends.7.000D9E48 at leeds.ac.uk>, gends at leeds.ac.uk (SCOTT D.)
says:
>>Hia,
>I need an accurate method of measuring protein concentration. My sample
is an
>RNA binding protein, and for various reasons very difficult to get rids
of the
>nucleotide without also getting rid of your sample. The prescence of the
>nucleotide is not inhibitory on the studies I'm carrying out, but it is
>providing just a few problems in estimating how much sample is there.
>Absorbance provides anomalous answers, and Biorad (Bradford) assays are
out as
>the answer needs to be accurate to within 5%. Amino Acid analysis tells
us
>accurately how much protein is there, but I'd love a way of doing this
in less
>than two days!
>So is there any ideas out there? Has anyone come across similar
problems,
>pointers in the right direction and information on dead ends not to
pursue
>would be very much appreciated!
>Cheers in advance,
>>Dave Scott.
>Dept of Genetics.
>University of Leeds.
>U.K.
>Email: gends%south-01.novell.leeds.ac.uk at gps.leeds.ac.uk
Hi Dave,
if you have enough smple, you should load an aliquot on a SDS-PAGE
You can measure the absorption of the Comassie-stained protein
in the SDS-PAGE with laser densitometers or flat bed scanners.
Or you could do an amino acid analysis of your sample, this would
give you the most accurate values. You will need at least
50pmol of protein for correct AAA.
Hope this helps
Andreas
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* University of Cologne Fax.: (49)-221-470-5181 *
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