Pouring sequencing gels

[Craig Echt]

dtyyu at ucla.edu (David Tak Yan Yu) wrote:
>We pour sequencing gels the ususal way.  It takes some time to teach newcomers
>in the lab.  Does any one has an easy way which does not require expensive
>apparatus?
>David Yu
>dtyyu at ucla.edu

A very simple method is to clamp the sides of the assembled gel using only side spacers, leaving the bottom open.  Support the horozontal assembly at its edges with 2 or 4 pipet tip boxes (supporting in the middle causes the plates to bow).  With one hand tip the assembly, with the other slowly inject the acrylamide solution from a 60 ml syringe using a back and forth motion across the top of the assembly.  As the solution nears the bottom the tipping angle may be decreased or returned to horozontal.  Capillary forces prevent the gel from leaking out the bottom, provided not too much solution is added.  The only problem is that this method requires very clean plates, otherwisenon-wetable areas  create bubbles or gaps. Clean plates can be obtained by polishing with cerium oxide powder (Millard and de Couet 1995 BioTechniques 19:576).

However, we now use The Otter gel caster sold by Owl Scientific.  It uses a horozontal sliding plate method that is very forgiving of less-that-perfectly-clean plates.  The apparatus is based on one described by Lashkari et al (1995 BioTechniques 18:626).  It costs $235.

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Craig S. Echt
Research Geneticist, USDA Forest Service

Forestry Sciences Lab        e-mail: cecht at newnorth.net
5985 County Rd. K             Ph: (715) 362-1114
Rhinelander, WI 54501      fax: (715) 362-1166
USA