From: Jo Butler <pjgb@mrc-lmb.cam.ac.uk>
  To  : RASMB-Noticeboard <rasmb@alpha.bbri.org>
  Date: Fri, 19 May 2000 11:58:41 +0100

Thin centr pieces

Dear RASMBers

I have been following the discussion on using thin polythene centrepieces
with interest.

Among other points, it reminds me of the time when Fred Sanger, while
developing his methods for sequencing DNA, abandoned the then normal thick
spacers for ones cut from thin material.  This gave the ultra thin gels
which allowed electrophoresis at high voltage, without too much heat, and
also a thin sample for the autoradiography, thus sharpening the bands.
Fred used "Plasticard", which I think was nylon and it came in a choice of
thicknesses.

I also remember the punches one used to use to cut out sealing gaskets for
the aluminium centrepieces when using them in the model E.  However, I have
one technical question to ask.  How does one insert the samples?   (The
aluminium centrepiences have the usual filling holes and it hardly seems
possible to have sample wells, and filling slots, in such a thin
centrepiece.)  Do you measure out a calculated volume, as a drop on the
lower window, and then flatten it into place with the upper window, or is
there some better technique?

With thanks in anticipation of the replies which I expect to receive.

Yours

JO

P.J.G. Butler,
MRC Laboratory of Molecular Biology,
Hills Road,
Cambridge, CB2 2QH,
UK.