DNA dyes

Brian_D Lanoil lanoilb at ava.bcc.orst.edu
Wed Aug 16 11:28:16 EST 1995

In article <40pgj9$7ah at nntp.ucs.ubc.ca> you write:
>A company called Molecular Probes Inc. located in Eugene Oregon sells a green dye which they 
>claim is quite a bit more sensitive than ethidium bromide for detecting DNA.  I haven't used 
>it, but I am planning to give it a try within the next couple of months.  So if you try it, 
>let me know how it well it works for you.
>Gary C. Donaldson
>Dept. of Plant Science, University of B.C.
>E-mail:  garyd at unixg.ubc.ca
>              donaldson at bcr.bc.ca
>              72700.2227 at compuserve.com
>There are three kinds of lies.  Lies, damn lies, and statistics.
>                                                                                  -Mark Twain

I did try it a while back, and I found little difference between SYBR 
Green and EtBr.  In fact, there was a disadvantage that I saw--the 
exposure times you need to use for imaging the SYBR Green-stained gel was 
10-fold longer than for EtBr.  It is true that there is no background at 
all, but the signal was so faint that I couldn't see it with my eye 
alone, even at high DNA concentrations.  

The main advantages I saw to SYBR green is that it does not appear to 
interfere with restriction digestion, unlike EtBr, and that, if you want 
to, and can, do two minute exposures with no outside light exposure, then 
you could detect DNA at a much lower concentration.  Good for some uses, 
poor for others.

This is from my own tests for my own uses, and perhaps I was using the 
product incorrectly (I borrowed it from someone else--it seems that 
Molecular Probes has a policy of not giving free samples for testing).  
Others let me know what you thought.


Brian D. Lanoil   Department of Microbiology
Oregon State University   Nash 222
Corvallis, OR 97331   (503)737-3334
lanoilb at bcc.orst.edu
"Quippy quote here..."

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