From: Arturo Morales <art@scripps.edu>
  To  : rasmb@alpha.bbri.org
  Date: Sat, 20 Nov 1999 13:55:21 -0800

Help... what's going on?

Dear RASMBers...

I just did a velocity run and something annoying happened...

I scanned 2 wavelengths in three cells, with 2 minute separations between 
scans (at 50K) If I plot every tenth scan (even numbers for wavelenght #2) 
I get the following: (at 235 nm)

http://schimmel.scripps.edu/art/velocity.jpg

those scans are not evenly spaced as I would expect...

at 280, it is way too noisy, but that's expected since there's no Trp's in 
the sample, and the protein is at 30 uM concentration only...I got similar 
behaviour from the other 2 cells... (even though they are independently 
purified mutants)

We just cleaned the lamp and it showed intensities of about 8-12 thousand 
in the scan...

Any ideas? can I trust a fit from this data? is there something wrong with 
the machine? can my sample have this effect?  (I did runs about a year ago 
on the same protein (different sample, of course) and it did not show this 
behaviour...

Thanks!

Art


--
Arturo J. Morales    (RPI '94)       --       art@scripps.edu
Department of Biology - Massachusetts Institute of Technology &
Skaggs Institute for Chemical Biology - Scripps Research Institute
                    http://schimmel.scripps.edu/~art