Fw: EtBr absorbance

Deanne Bell dbell at qnis.net
Thu Mar 15 11:21:54 EST 2001

Do you stain your gels in 0.1ug EtBr per ml?  I think SOP is around 1ug per
ml (that would mean 10ul as jakku suggested).
IMHO if the person who asked the original question wants only to stain a
gel, maybe they should do a trial and error type of thing.  You know . . .
Start with 5ul of "stock" solution in 100ml water.  Stain for 15 - 30 min,
rinse, and visualize.
If bands on the ladder are not bright enough, re-stain the same gel with
10ul of "stock" . . . there might be a little diffusion of the bands but it
should still be OK to read.

I got the impression that this person was trying to do something else
though.  If you are still out there, why do you want to know the
concentration of the EtBr Solution?
D Bell

> From: "Michael L. Sullivan" <mlsulliv at facstaff.wisc.edu>
> To: methods at hgmp.mrc.ac.uk
> Subject: Re: EtBr absorbance
> Date: Thursday, March 15, 2001 6:39 AM
> If you use only 1ul of 10 mg/ml EtBr per 100 ml directly in the gel it
> works fine to stain.  AND this generates much less waste.
> Mike
> >hi...
> >   why do you want to know the concentration of ethidium bromide
> >If it is for staining DNA gels, I don't think you need to bother much
> >concentrations whether it be 10 or 20mg/ml.  Just addd a little of this
> >water or buffer and you should be able to stain it.  around 10/20ul to
> >ml of solution.
> >    bye
> >jayakumar
> >
> Michael L. Sullivan, Ph.D
> U.S. Dairy Forage Research Center
> 1925 Linden Drive West
> Madison WI, 53706
> (608) 264-5144 Phone
> (608) 264-5147 Fax
> ---


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