From: Michael Morris <michaelm@pharm.usyd.edu.au>
  To  : schirfv@bioc02.uthscsa.edu
  Date: Mon, 12 Jan 98 10:10:52 EST

Re: Punches for gaskets

At 11:01 AM 1/9/98 -0600, you wrote:
>We would like to know if anyone has made a punch to hand cut the gaskets
>used with the double sector aluminum centerpieces and whether or not the
>material is the same as the cell plug gaskets.  Any help would be
>greatly appreciated.
>
>____________________________________________________________________
>Center for Analytical Ultracentrifugation of Macromolecular Assemblies
>Department of Biochemistry
>UT Health Science Center
>TEL:  (210) 567-6590
>FAX:  (210) 567-6595
>schirfv@bioc02.uthscsa.edu
>
>
>

Dear schirfv@bioc02.uthscsa.edu,

Yes, a punch has been made - a two-part one that does the outer circle and
then the two part-circles inside. The material for the gaskets is the same
as the cell plug gaskets.

The punch works quite well. Problems (cell leakage) appear to depend heavily
on the quality of the edges of the gaskets. This, in turn, seems to depend
heavily on the properties of the surface on which the punching is done. The
Ralston lab settled on woven nylon which seems to 'yield' sufficiently
during punching and provides a durable surface. The benchtop or a block of
wood (various hardnesses) were not as successful.

Yours, Michael
______________________________________________________________________

Michael Morris                   
Pharmaceutical Chemistry            ph: +61-2-351-2359              
Department of Pharmacy A15          fax: +61-2-351-4391                
University of Sydney 2006           email: michaelm@pharm.usyd.edu.au

Australia
______________________________________________________________________