Agarose Gels

[Steven_H Harwood]

On 25 Apr 1995, Biology Department wrote:

> 	Recently, our gels have been running slanted--if you view the gel 
> from the side the bands are diagonal to the horizontal plane of the gel.  
> We have remade our buffer (1XTAE) but this does not seem to help.  Any 
> suggestions as to the cause of this problem?  The major difficulty is 
> that if you view the gels from above the bands appear fuzzy and wide 
> instead of sharp. Any comments would be appreciated.

I've had the same experience.  I have had some success adjusting my 
methods with regard to the following considerations:

1. Too much DNA per band.  Sambrook et al. 1989 suggest that 0.8 ug DNA 
is the most that can be satisfactorily resolved in a 0.5 cm band.  To try 
to get the smaller bands, I tend to overload my lanes, especially with 
minipreps.

2.  Electric field too strong.

3.  Sample loaded too high in the wells.  When pouring horizontal gels, 
the meniscus around the combs causes the well to be deeper than the 
actual slab.  The sample shouldn't be deeper than the slab itself.

Hope this helps.

Steve Harwood
Dept. Ag. Chem.
Oregon State University
Corvallis, OR  97331
>