From: Allen Furst <AFurst@beckman.com>
  To  : rasmb@alpha.bbri.org
  Date: Wed, 17 May 2000 15:03:05 -0700

Re: Further mud in the water

Neil Errington writes questions about using thin centerpieces. We have just
begun doing some experiments with a 6-channel, 3mm centerpiece, using BSA in
equilibrium runs. Using different combinations of spacers, the centerpiece can
be positioned at various places in the optical pathlength, approximately 2/3 and
1/3. Surprisingly, I haven't seen any difference between these two positions, at
least in a preliminary run. I am also curious as to the experiences others may
have had, and as to any ideas of what I should be looking for in the data
pattern to indicate that the instrument is focussing improperly.
af