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<TITLE>RE: [RASMB] FC43 fluorocarbon silicon oil</TITLE>
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<P><FONT SIZE=2>Joris,</FONT>
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<P><FONT SIZE=2>The FC-43 oil can be purchased through a distributor from 3M. The 3M part number is 9800204-0101-8.</FONT>
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<P><FONT SIZE=2>I guess we must be old-fashioned, too. A little oil in the bottom works well for squeezing a few more data points from the cell bottom. For some of our proteins in certain buffers, though, we can't use the oil as it somehow changes the equilibium constant. </FONT></P>
<P><FONT SIZE=2>Have a great day!</FONT>
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<P><FONT SIZE=2>Cheryl</FONT>
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<P><FONT SIZE=2>********************************************* </FONT>
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<P><FONT SIZE=2>Cheryl A. Blasie, Ph.D. </FONT>
<BR><FONT SIZE=2>Centocor, Inc. </FONT>
<BR><FONT SIZE=2>145 King of Prussia Rd. </FONT>
<BR><FONT SIZE=2>Radnor, PA 19087 </FONT>
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<P><FONT SIZE=2>Phone: 610-889-4447 </FONT>
<BR><FONT SIZE=2>FAX: 610-651-6303 </FONT>
<BR><FONT SIZE=2>Mail stop: R-1-1 </FONT>
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<P><FONT SIZE=2>email: cblasie@cntus.jnj.com </FONT>
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<P><FONT SIZE=2>********************************************* </FONT>
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<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: rasmb-admin@server1.bbri.org</FONT>
<BR><FONT SIZE=2>[<A HREF="mailto:rasmb-admin@server1.bbri.org">mailto:rasmb-admin@server1.bbri.org</A>]On Behalf Of Beld, Joris</FONT>
<BR><FONT SIZE=2>Sent: Monday, May 09, 2005 6:05 AM</FONT>
<BR><FONT SIZE=2>To: RASMB@server1.bbri.org</FONT>
<BR><FONT SIZE=2>Subject: [RASMB] FC43 fluorocarbon silicon oil</FONT>
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<P><FONT SIZE=2>Dear all,</FONT>
<BR><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Maybe we are old fashioned but we still like to put a little bit (20-30 ul) of FC43 fluorocarbon silicon oil in the bottom of the sample sector (two sector centerpiece) during a sedimentation equilibrium run. Just to create a false bottom and prevent scatter problems at the edge (bottom) of the cell. Works fine and has been used a lot in the past. Lately we are almost running out of the oil, so I contacted Beckman and they told me the following:</FONT></P>
<P><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>"The fluorocarbon oil (306394) was used as part of the cell assembly and</FONT>
<BR><FONT SIZE=2>added to the sample side of the 6- channel centerpiece to "lift" the sample in</FONT>
<BR><FONT SIZE=2>the outer most sector above the cell bottom in order to collect more data in</FONT>
<BR><FONT SIZE=2>that area. This approach was abandoned when the cell holes were</FONT>
<BR><FONT SIZE=2>realigned shortly after the product launch near 1993 to better match the optical</FONT>
<BR><FONT SIZE=2>track of the instrument. I don't recall the exact date, but the oil has been</FONT>
<BR><FONT SIZE=2>discontinued for several years with no recommended replacement since it is no</FONT>
<BR><FONT SIZE=2>longer needed."</FONT>
<BR><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Does anyone know what the composition of this FC43 fluorocarbon silicon oil is (or does someone knows another source from which we can buy it)? (I asked Beckman but so far they do not want to give us the composition)</FONT></P>
<P><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Of course I can forget about the oil and just do runs without it but for reproducibility and comparison with previous experiments we would really like to have some.</FONT></P>
<P><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Thanks in advance.</FONT>
<BR><FONT SIZE=2>Kind regards,</FONT>
<BR><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Joris Beld</FONT>
<BR><FONT SIZE=2>Swiss Federal Institute of Technology</FONT>
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