From: Michael Jacobsen <jacobsen@biosci.uq.oz.au>
  To  : demeler
  Date: Thu, 23 Jun 1994 10:08:21 +1000

Aluminium centrepieces

Borries,

For what its worth, I have found that the red polyvinyl gaskets acquired 
from Beckman are prone to some form of leeching. When used in some 
experiments using BSA in acetate buffer (pH ~5)(what I would consider mild 
conditions for this centrepiece) the observations were made that a reddish 
dye residue remained on the aluminium surface upon removal of the gaskets 
from the centrepiece. I enquired further with Beckman both here in Australia 
and the States as to possible causes. No conclusions were made then or 
since. Not all the gaskets left this residue, so it may have been age 
related since some of the gasket lots were quite old. The effect on 
absorbances were not ascertained then or since but this may be a worthy note 
for users of the XL-A. I am having some tool dyes constructed to so as to 
make these gaskets but have not made any serious attempt towards finding a 
suitable alternative to the "red polyvinyl" supplied by Beckman.

Michael P. Jacobsen
Centre for Protein Structure, Function and Engineering
Biochemistry Department
University of Queensland
St. Lucia 4067
Australia.


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e-mail:<jacobsen@biosci.uq.oz.au>