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Hello All,<br>
We have recently purchased an XLI and I have some questions regarding the
interference optics that I am hoping some of you can help me with. My problem
is basically non-linearity of the scans, and correction of that non-linearity
using a blank scan correction. <br>
<br>
Firstly, when scanning an empty rotor hole the slope of the best fit line
to the resulting data is about 0.2 finges/cm (well outside Beckman’s specs
of 0.04 fringes/cm). Scan's of an empty cell are comparable. Beckman is
not terribly concerned about this and will have a service rep align the camera
to try and improve, they suggest that if I just do the appropriate blank
scan subtraction everything will be OK (confidence that I do not share!).
<br>
<br>
Which brings me to my next, more troubling, concern - blank scan subtractions.
Subtraction of a blank scan taken of the same empty rotor hole, empty cell
or water cell does not always give me a flat baseline, particularly when
I use the option of subtracting a previously saved scan. When dealing with
only one cell the result is fine, however when I do several cells in one
scan only the one whose baseline was scanned last is flat, all the rest have
a significant deviation from zero. I think what’s happening is that even
though all cells have a blank file (blank.ipx) all the subtractions are using
the last file scanned. We have version 4.5 of the data acquisition software
and it doesn’t have an option to select an actual scan so I’m assuming that
it should just use whatever the last blank.ipx is for the relevant cell.
I have tried deleting some of these blank files and the software is looking
for them – apparently just not using them. Can anyone shed any light on this?<br>
<br>
While I agree that I need not worry about this non-linearity for our g*(s)
analysis, I am trying to get good equilibrium data for a system that we have
to use interference for (buffer contains nucleotide) and I am sure this is
causing a problem. Any suggestions or information would be appreciated.<br>
<br>
Thanks <br>
<br>
Lisa<br>
<div class="moz-signature">
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<hr width="100%" size="2"><font face="Helvetica, foo, sans-serif"><big>Lisa
Joss</big>
</font><font face="Helvetica, foo, sans-serif"> (801) 585-3919</font><br>
<font face="Helvetica, Arial, sans-serif">Postdoctoral Fellow
email: <a class="moz-txt-link-abbreviated" href="mailto:ljoss@biochem.utah.edu">ljoss@biochem.utah.edu</a><br>
</font>
<pre wrap=""><font face="Helvetica, Arial, sans-serif">UNIVERSITY OF UTAH<br>BIOCHEMISTRY<br>20 N 1900 E RM 211<br>SALT LAKE CITY UT 84132-3201</font></pre>
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