[RASMB] Assembled cells using aluminum centerpiece won't fit in rotor

[Tom Laue]

Hi John-
I concur with what Virgil and Dmitry have said- the problem usually is 
that the housing is out of round, and that over-tightening of the fill 
hole screws is the most common cause.
A couple of things-

 1. You can use any of the Epon centerpieces at 60k rpm. The only
    problem occurs if they leak out one side, in which case the septum
    will split.  We routinely run our epon centerpieces at 60k.
 2. The Spin60 centerpieces work fine on some XLA/I's, but there are
    some instruments where the lamp timing causes excess noise in the
    absorbance readings. For the Beckman absorbance system, I would
    recommend either the Spin50 or the standard Beckman centerpieces...
    the Spin50s cost quite a bit less and work just as well.
 3. If you need chemical resistance (particularly if you are working
    with organic solvents), I would recommend using Nanolytics titanium
    centerpieces.
 4. Spin Analytical sells a fill hole gasket kit that includes gasket
    material (neoprene or teflon), a punch and, most importantly, a
    torque screw driver and hex-head screws. Using the hex-head screws
    is a heck of lot easier than using the slotted screws. Using the
    neoprene or teflon provides a much better seal than the red PVC
    gaskets. The torque screw driver ensures that you will get a good
    seal and not warp your cell housings. You can get more information
    at www.spinanalytical.com

Best wishes,
Tom

On 3/6/2012 5:54 PM, john_doran at vrtx.com wrote:
> Greetings all,
>
> We just purchased some of those expensive aluminum centerpieces so we 
> can run experiments at greater than 50 K but there is a small problem, 
> the assembled cells won't fit into the rotor! Has anyone ever seen 
> this problem before and is there some obvious fix I am not seeing? 
> Thank you in advance for any suggestions!
>
>
>
> John D Doran, Ph.D.
> Protein Biochemistry
> Vertex Pharmaceuticals Inc.
> 130 Waverly Street
> Cambridge, MA 02139
> 617-444-6142
>
>
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> RASMB at rasmb.bbri.org
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-- 
Department of Biochemistry and Molecular Biology
University of New Hampshire
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Phone: 603-862-2459
FAX:   603-862-0031
E-mail: Tom.Laue at unh.edu
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