[RASMB] Re: peculiar leakage problem!

[sumit goswami]

If I allign the cell properly wouldn't I expect the screw hole to orient
towards the center properly?
I indeed didn't mention what material I used. I used charcoal filled epon
centerpiece. Recommeneded speed 42000rpm but we routinely use it at 50000rpm
like many other people. But the speed doesn't solve it as the same cell
assmebly that didn't leak with water leaked with the protein sample the very
next time.

Sumit



On Fri, Jun 12, 2009 at 4:51 PM, sumit goswami <ikant11 at gmail.com> wrote:

> Dear all
>             we have been trying do some sed-velocity experiments for last
> couple of weeks but every time we tried most of the cell assemblies leaked!!
> Apparently it seemed like a simple problem of aging of center pieces but
> then very recently I ran all the seven cell assemblies overnight at 50000rpm
> with water in them and none leaked! After that I used the same set of
> assembly for running my sample by sucking off the water from them  and 4 out
> of 5 leaked even at 4000rpm. We have used different kinds of buffer so
> far... PE (5mM Na-phosphate, 1mM EDTA), TE (10mM Tris, 1mM EDTA), Poly
> buffer (MES,tris, acetate). All of our buffer had 0.01%PEG in them. We have
> tried both PH 5 & 8.
>    Can anyone suggest what's going on? We are ready to buy new centerpiece
> but not sure if that's the problem. The result with water is confusing us!
>
> Thank you very much!
>
> Regards,
> Sumit
>
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