[RASMB] SedVel60K centerpieces

[pjgb at mrc-lmb.cam.ac.uk]

Dear RASMBers,

For what it is worth, we routinely use Beckman epon centrepieces at 60K for 
velocity runs employing absorbance optics (and also, more recently since 
purchasing an XLI, interference) and have experienced no problems to 
suggest any trouble with light reflecting off the surfaces.
As Virgil has said, we also have had the septum break when there has been a 
leak, but this is a reasonably rare event and we certainly think that on 
balance, of accepting the cost of replacements occasionally, outweighs the 
hassle of using gaskets with any metal centrepiece.

Jo

--On Wednesday, August 24, 2005 4:55 pm -0500 John Correia 
<jcorreia at biochem.umsmed.edu> wrote:

>
> RASMBers
>
> To my knowledge I am the only person to report noisy scans with the
> SedVel60K centerpieces - we suspect a timing issue in the XLA that only
> manifests itself with the narrower sectors - its worse at low radius than
> high is the evidence for this - and in fact we are working on a delay
> calibration issue on my machine as I write this.  CAMIS is also replacing
> the centerpieces to be sure they are not a defective batch.  So rather
> than judge the centerpieces on apparently one report, how about some
> data.  How many labs successfully have used SEDVEL60K centerpieces? How
> many labs have experienced timing or noise issues with the SEDVEL60K
> centerpieces?
> -------------------------------------------------------------------
>  Dr. John J. "Jack" Correia
>  Department of Biochemistry
>  University of Mississippi Medical Center
>  2500 North State Street
>  Jackson, MS  39216
>  (601) 984-1522
>  fax (601) 984-1501
>  email address: jcorreia at biochem.umsmed.edu
>  homepage location: http://biochemistry.umc.edu/correia.html
>  dept homepage location:    http://biochemistry.umc.edu/
> -------------------------------------------------------------------
>
>



P.J.G. Butler,
MRC Laboratory of Molecular Biology,
Hills Road, Cambridge, CB2 2QH, UK.
Tel. +44 (0)1223 402296