Smiles in agarose gels

[Landry Pierre-Alexandre]

Hello everyone.

	In order to separate DNA fragments obtained from RAPD, I make the 
amplification samples run through an horizontal agarose gel. 
Unfortunately, I always get this "smile" that bends all the bands and 
makes the gel analysis much more complicated. The gels are 1,5%, and I've 
tried different voltages from 20 to 80 volts, and although I noticed that 
the "smile" is reduced with decreasing voltages, it isn't clear enough to 
allow a perfect analysis. I'd be glad to hear any suggestion, advice or 
magic trick to improve the situation.

Thanks in advance.

Pierre-Alexandre Landry
Dept. des Sciences Biologiques
Universite de Montreal
C.P. 6128, succursale centre ville
Montreal, Quebec
H3C 3J7