DNA staining

[WMELCHIOR at NTDOC.NCTNET.GOV]

I am helping develop an experiment for high school students
involving agarose gel electrophoresis of DNA.  My question is,
what stain should we use.  I have read that methylene blue
can be used -- this would avoid the use of the mutagenic
ethidium bromide and of ultraviolet light, which would be
desirable for working with a group of students.  On the 
other hand, I'm worried that the sensivity would not be 
high enough.  I'd like to keep to less than a microgram
of DNA per band.

Does anyone have experience with methylene blue staining
of agarose gels?  I haven't been able to find anything
in my "standard" reference works about how to use it or
how sensitive it is.  Or are there other non-hazardous
stains I should investigate?  (I need advice on staining 
solutions, such as dye concentration and buffer components,
as well as destaining solutions and procedures.)

I'm anxious to help my teacher friend develop an
exciting but safe experiment.  Any help will be much
appreciated.


Bill Melchior      

National Center for Toxicological Research
Jefferson, AR  72079
(501) 543-7206

wmelchior at ntdoc.nctnet.gov