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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear RASMB,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks to everyone who responded to my previous question regarding the linearity of density and concentration. Although I am not completely resolved in this yet, for the time being I’ve decided to work in a range where our measurements appear to be linear and thus reasonable and understandable. All the comments received were, as always highly informative and very helpful. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have another question along the same lines. According to a lot of previous work it does seem that it is accepted given that v-bar is, for the most part, a constant for most proteins, and that the density is likewise a constant at a given solution composition and temperature, the density increment, (1-vp), is therefore also accepted to be constant. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Two questions:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Am I correct in thinking this? <o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Can the density increment of a solution be used to convert the density to concentration as it is stated in “Adair et. al. Density increments of proteins. Proc. Royal Soc. Lond, A Math Phys Sci 1947 pp.190_34”?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thank you again for all the helpful pointers.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>John Sumida, Ph.D.<o:p></o:p></p><p class=MsoNormal>Analytical Biopharmacy Core<o:p></o:p></p><p class=MsoNormal>University of Washington<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>