From: Neil Errington <neil.errington@nottingham.ac.uk>
  To  : RASMB Bulletin Board <rasmb@alpha.bbri.org>
  Date: Wed, 17 May 2000 14:54:51 +0100

Re:further mud in the water

Dear all

just to throw some further mud into the water on the small path-length
centrepieces issue:

1) there could be a problem with optics involved here. If your optics are
focussed slightly off-position you may end up being focussed very close to
or actually in a window with these centrepieces instead of in your solution.

2) This is true with any thickness of centrepiece but, if your sample is
very "sticky" and adheres to your window, would this not also cause a lot of
problems with very thin centrepieces and high sample concentrations?

Maybe people out there who often use these centrepieces have got these
problems sorted out already, but it would be nice to hear their
solutions/thoughts on the problem.

All the best to everyone

Neil Errington


**************************************************
Dr Neil Errington
Manager, NCMH Business Centre
School of Biological Sciences
University of Nottingham
Sutton Bonington
Leicestershire.
LE12 5RD. UK

Tel: +44 (0)115 951 6156
Fax: +44 (0)115 951 6157
URL: http://www.nottingham.ac.uk/ncmh/business

*************************************************


>This has been an interesting and enlightening discussion.  The modified cell
>construction is also of interest to those of us in the industrial community
>looking at what happens to our products in process and in formulations.  It
>is not unusual for a biopharmaceutical to spend time at concentrations in
>the 30+ mg/ml range, and we sometimes have to look at high concentrations to
>answer questions for the regulatory agencies.  I have used the 3 mm
>centerpieces in sedimentation velocity studies, and it isn't difficult to
>imagine needing to get 1 mm cells at some point in the future.  Does anyone
>know if Beckman or anyone else would do a special order for something like
>this for those of us who don't have ready access to an appropriate machine
>shop?  (If any Beckman folks are reading this, consider it a product hint.)
>I am interested in getting a contact and a lead time in case I need to get
>some really thin cells for my studies, and there may be some others
>interested in this type of information as well.
>