Help explain my DNA bands smearing

ryan at ryan at
Tue Sep 26 17:20:41 EST 1995

In article <445jck$g5c at>, j140474 at writes:
> 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. No bands can be made out at all. The markers came out all righ. 
> What is the smearing due to? Was it caused by multiple site restriction?
> Can I solve the problem?
> Anybody who can help please post back a reply to this Newsgroup. Thanks! 

Hi Jene,

How did you visualize your DNA? Blot hybridization to a specific probe DNA will
light up only fragments that contain bases complementary to the probe. Staining
with e.g. ethidium bromide will show all fragments, all sizes (i.e., a smear).

	Kevin W. Ryan
	Department of Virology & Molecular Biology
	St. Jude Children's Research Hospital
	Memphis, Tennessee 38101-0318, U.S.A.
	phone: (901) 495-3411
	fax:   (901) 523-2622
	Internet: ryan at

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