[RASMB] What is wrong with my XLA?

[smcbryan]

Fellow centrifugationistas, 
Attached find two .png files of 1) two sample meniscus regions from data
collected in the intensity mode at 280nm, and 2) the resulting data from
one of these samples after time independent noise subtraction. 
almost certainly there is a problem with my slit assembly, resulting in
the menisci which defy fitting. My question is, is the very anomalous data
(which does not fit via van Holde-Weischet analysis)a result of ONLY the
meniscus jumping about, or is there perhaps another cause superimposed on
the slit assembly? 
Finally, there is a noise signature at 6.35cm in all sectors of all cells
always with this machine. I have cleaned the glass filter in the bottom of
the rotor chamber that protects the lamp, and blown some compressed air
gently into the slit in the monochrometer assembly. Neither act has removed
the offending noise. Any further suggestions for removal are appreciated. 
cheers, 
steve


-- 
Steven McBryant, PhD
Director
Protein Production and Characterization Facility
Research Scientist/Scholar
Colorado State University
970-491-5586
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