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<DIV dir=ltr align=left><SPAN class=339050017-30092011><FONT color=#0000ff
size=2 face=Arial>Anamika, your attachment did not come through, but most likely
this is not a radial calibration problem. Assuming the apparent positions of the
sample and reference meniscus are moving to higher radius over time, that would
be consistent with a slow leak (probably the red fill-hole gaskets have not
produced a complete vacuum seal). If you search through the archives you will
find discussions about such problems and alternatives to the red gaskets from
Beckman.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=339050017-30092011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=339050017-30092011><FONT color=#0000ff
size=2 face=Arial>Without seeing the data it is hard to say much about the
impact on the data analysis, but definitely any leakage of the sample could
significantly impact the sedimentation coefficients and the detection of minor
components. You may be able to minimize the impact by fitting for the meniscus
position, and if all you are trying to do is to distinguish whether your main
species is a monomer versus dimer that conclusion would likely be valid, but
sorry, I probably wouldn't trust this experiment for any critical
results.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=339050017-30092011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=339050017-30092011><FONT color=#0000ff
size=2 face=Arial>John</FONT></SPAN></DIV>
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<DIV dir=ltr align=left><FONT size=2 face=Tahoma><B>From:</B>
rasmb-bounces@rasmb.bbri.org [mailto:rasmb-bounces@rasmb.bbri.org] <B>On Behalf
Of </B>Anamika Patel<BR><B>Sent:</B> Friday, September 30, 2011 8:01
AM<BR><B>To:</B> RASMB@rasmb.bbri.org<BR><B>Subject:</B> [RASMB] sedimentation
velocity data<BR></FONT><BR></DIV>
<DIV></DIV>
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<DIV dir=ltr><FONT color=#000000 size=2 face=Tahoma>Dear RASMB
subscribers,</FONT></DIV>
<DIV dir=ltr><FONT face=tahoma></FONT> </DIV>
<DIV dir=ltr><FONT face=tahoma>We collected some sedimentation velocity
data on AUC (XLA) and happed to notice a problem with our mechine with
radial cabritation. As a result of that in our data the sample as well as
refrence mesicuse drifted a lot from scan to scan. It seems that we need some
fixing with our AUC but meanwhile I was wondering if there is any way to analyze
the data which I have already collected. I have atatched a snapshot of my data.
Any suggestions or advice would be highly appreciated.</FONT></DIV>
<DIV dir=ltr><FONT face=tahoma></FONT> </DIV>
<DIV dir=ltr><FONT face=tahoma>Thanks</FONT></DIV>
<DIV dir=ltr><FONT face=tahoma></FONT> </DIV>
<DIV dir=ltr><FONT face=tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>Anamika Patel, Ph.D.</FONT></DIV>
<DIV><FONT size=2 face=tahoma>Department of Biology</FONT></DIV>
<DIV><FONT size=2 face=tahoma>Life Science Complex</FONT></DIV>
<DIV><FONT size=2 face=tahoma>Syracuse University</FONT></DIV>
<DIV><FONT size=2 face=tahoma>107 College place</FONT></DIV>
<DIV><FONT size=2 face=tahoma>Syracuse- 13244</FONT></DIV>
<DIV><FONT size=2 face=tahoma>NY</FONT></DIV></DIV></BODY></HTML>