<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1445286759039_3226"><span id="yui_3_16_0_1_1445286759039_3227">Hi Karl,</span></div><div id="yui_3_16_0_1_1445286759039_3226"><span><br></span></div><div id="yui_3_16_0_1_1445286759039_3226"><span id="yui_3_16_0_1_1445286759039_3290">Please note that the two scan sets are from the same cell, same sample, on different machines, and the cell was not in any way cleaned up between the two. Any dirt on the outside of the cell would show up in both. Also, the noise moves around the cell and is time dependent. </span></div><div id="yui_3_16_0_1_1445286759039_3226"><span><br></span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span id="yui_3_16_0_1_1445286759039_3439">A while back I had a cell with a big splatter on just the sample window and it made a baseline that was around 0.2 A280 at the base of the cell. SEDFIT did fine fitting this data set, though it looked like a curvy rainbow at the bottom of the cell: the baseline did not change with time, so SEFIT could fit it.</span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span id="yui_3_16_0_1_1445286759039_3499">We always have sample/dirty cell discussions with our Beckman repair man, so we are well trained in making sure the noise comes from the instrument and not the cell or sample.</span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span id="yui_3_16_0_1_1445286759039_3500">Kind Regards,</span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1445286759039_3226" dir="ltr"><span>David</span></div><br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1445286759039_3166"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1445286759039_3165"> <div dir="ltr" id="yui_3_16_0_1_1445286759039_3164"> <hr size="1" id="yui_3_16_0_1_1445286759039_3314"> <font size="2" face="Arial" id="yui_3_16_0_1_1445286759039_3225"> <b><span style="font-weight:bold;">From:</span></b> Karl Maluf <Karl.Maluf@ap-lab.com><br> <b><span style="font-weight: bold;">To:</span></b> 'David Hayes' <drdavidbhayes@yahoo.com>; 'RASMB' <rasmb@rasmb.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, October 19, 2015 4:12 PM<br> <b id="yui_3_16_0_1_1445286759039_3502"><span style="font-weight: bold;" id="yui_3_16_0_1_1445286759039_3501">Subject:</span></b> RE: [RASMB] Strange AUC noise<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1445286759039_3177"><br><div id="yiv2949956042"><div id="yui_3_16_0_1_1445286759039_3176">
<div align="left" dir="ltr" id="yui_3_16_0_1_1445286759039_3175"><span class="yiv2949956042909430920-19102015" id="yui_3_16_0_1_1445286759039_3504"><font color="#0000ff" id="yui_3_16_0_1_1445286759039_3503">David,</font></span></div>
<div align="left" dir="ltr" id="yui_3_16_0_1_1445286759039_3224"><span class="yiv2949956042909430920-19102015"><font color="#0000ff"></font></span> </div>
<div align="left" dir="ltr" id="yui_3_16_0_1_1445286759039_3218"><span class="yiv2949956042909430920-19102015" id="yui_3_16_0_1_1445286759039_3217"><font color="#0000ff" id="yui_3_16_0_1_1445286759039_3216">Are
you sure there wasn't a smudge on one the windows from someone's thumb as they
assembled the cell?</font></span></div>
<div align="left" dir="ltr" id="yui_3_16_0_1_1445286759039_3219"><span class="yiv2949956042909430920-19102015"><font color="#0000ff"></font></span> </div>
<div align="left" dir="ltr" id="yui_3_16_0_1_1445286759039_3220"><span class="yiv2949956042909430920-19102015"><font color="#0000ff">Karl</font></span></div><br clear="none">
<div class="qtdSeparateBR"><br><br></div><div class="yiv2949956042yqt2729790018" id="yiv2949956042yqt45082"><div align="left" class="yiv2949956042OutlookMessageHeader" dir="ltr" lang="en-us" id="yui_3_16_0_1_1445286759039_3221">
<hr tabindex="-1">
<font size="2" face="Tahoma" id="yui_3_16_0_1_1445286759039_3223"><b>From:</b> RASMB
[mailto:rasmb-bounces@list.rasmb.org] <b id="yui_3_16_0_1_1445286759039_3222">On Behalf Of </b>David
Hayes<br clear="none"><b>Sent:</b> Monday, October 19, 2015 11:14 AM<br clear="none"><b>To:</b>
RASMB<br clear="none"><b>Subject:</b> [RASMB] Strange AUC noise<br clear="none"></font><br clear="none"></div>
<div></div></div>
<div style="FONT-SIZE:16px;FONT-FAMILY:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;COLOR:#000;BACKGROUND-COLOR:#fff;">
<div class="yiv2949956042yqt2729790018" id="yiv2949956042yqt86411"><div id="yiv2949956042yui_3_16_0_1_1445277124881_2742">Hi all,</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2742"><br clear="none"></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">We had some strange AUC noise in a
recent experiment. In the pictures below from SEDFIT, the first two runs
produced data as in the picture NNBekman1 (the IT guys name our instruments and
they pruposely mispelled Beckman as Bekman years ago). A strange noise pattern
showed up in the scans that were produced on day one. Then the sample was
loaded into a new cell and run again on the same centrifuge producing the
strange noise pattern in the picture called NNBekman1. the filled cell
was taken and gently mixed and then run on another centrifuge Bekman17 and made
a perfectly fine patter shown in picture Beckman17.</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751"><br clear="none"></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">We have seen the strange noise before on
our NNBekman1 centrifuge, but this is the first time on NNBekman2.</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751"><br clear="none"></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">Has anyone seen noise like this?
</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">Any theories on the cause of the
noise?</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751"><br clear="none"></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">It certainly looks like an optical
artifact of some kind, but the time dependence is hard to explain.</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751"><br clear="none"></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">Kind Regards,</div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751"><br clear="none"></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751">David Hayes</div></div>
<div id="yiv2949956042yui_3_16_0_1_1445277124881_2751"><br clear="none"></div>
<div dir="ltr" id="yiv2949956042yui_3_16_0_1_1445277124881_2742"><span id="yiv2949956042yui_3_16_0_1_1445277124881_2764" style="FONT-SIZE:11pt;"><!--[if !vml]--><!--[endif]--></span><span id="yiv2949956042yui_3_16_0_1_1445277124881_2874" style="FONT-SIZE:11pt;"><!--[if
!vml]--><!--[endif]--></span><br clear="none"></div>
<div dir="ltr" id="yiv2949956042yui_3_16_0_1_1445277124881_2742"><br clear="none"></div></div></div></div><br><br></div> </div> </div> </div></body></html>