Help explain my DNA bands smearing

Rafael Maldonado rafael at howard.genetics.utah.edu
Mon Sep 25 16:27:15 EST 1995


On 25 Sep 1995, jene wrote:

> Hello, recently I did a gel electrophoresis on genomic DNA isolated from 
> Arabidopsis. The samples were restricted with MluI, EcoRI and SAU3A.
> I expected to see distinct bands of DNA but ended up with smears in all 
> my lanes. 

Why did you expect that? I would expect a big smear.

A smear is the result of many bands. With that digestion, you get many 
different bands, and the range of size is almost continous: there are 
many bands, each one very close to the next one. That because you don't 
see any band.

Most of the enzymes give a smear when you digest chromosomal DNA with 
them. Except, of course, those that cut very rarely in your genome. 
That's the theory of the pulsed filed electrophoresis.

	-Rafa

___________________________________________________________________
                                             |
Rafael Maldonado                             |  La cita ha sido
room 6160 Eccles Institute of Human Genetics |  
Department of Human Genetics		     |  retirada por respeto
University of Utah			     |
Salt Lake City, Utah 84112. USA.	     |  a la propiedad 
Rafael.Maldonado at genetics.utah.edu           |
Rafael at howard.genetics.utah.edu	             |  intelectual.
Tel: 801-581-4429			     |
Fax: 801-585-3910			     |
					                  






More information about the Methods mailing list