[RASMB] Fwd: negative concentrations? from Heather Peto

[Walter Stafford]

>Resent-Date: Mon, 15 Apr 2002 11:05:01 -0400
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>Date: Mon, 15 Apr 2002 15:50:29 +0100
>From: Heather Peto <hp217 at mole.bio.cam.ac.uk>
>To: <rasmb at server1.bbri.org>
>Subject: negative concentrations?
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>Hi I am new to AUC.  I have used the XL1 Beckman with interference optics
>to test the oligomerisation state of a small peptide (28AA's monomer 3kDa)
>for technical reasons we can't use absorbance.
>I get in my data file the first values of concentrations as negative
>numbers! Which means that I can not take the natural log of them to plot
>against r2.  I wonder what do the negative numbers means? Is this an
>artifact of interference optics giving ratios of concentrations rather
>than absolute concentrations.  What can I do with the data to make it
>available to interpretation?
>
>many thanks
>
>heather :)
>
>
>
>Heather Peto			   Department of Biochemistry
>hp217 at mole.bio.cam.ac.uk	   New Building
>Tel: (lab)    +44 (0)1223 333343,  80 Tennis Court Road
>Tel: (office) +44 (0)1223 766022,  Old Addenbrookes Site
>Fax:          +44 (0)1223 766002,  Cambridge, CB2 1GA
>				   UK

-- 
Walter Stafford
mailto:stafford at bbri.org
617-658-7808