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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> Hi. We recently ran sedimentation velocity on
some samples that contained 10% sucrose in the buffer. We obtained results for
the c(s) distribution that didn’t agree well with what we saw by SEC, and
the s-values were also shifted to significantly lower values than what we would
expect (and that we have seen in other formulations) for an IgG. It was
suggested to us that our sucrose concentration was high enough to create a
sucrose gradient in the cell during the course of the run, and that this could cause
the relative peak areas in the c(s) plot to be inaccurate.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> Does anybody have any comments about this, or suggestions
about how high in sucrose content you can go before this starts to become a
problem?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> Matt<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><st1:PersonName w:st="on"><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Matthew Parker</span></font></st1:PersonName><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>, Ph.D.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Analytical and Pharmaceutical Sciences</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Immunogen, Inc.<o:p></o:p></span></font></p>
<p class=MsoNormal><st1:place w:st="on"><st1:City w:st="on"><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Cambridge</span></font></st1:City><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>, <st1:State
w:st="on">MA</st1:State></span></font></st1:place><o:p></o:p></p>
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