Non-isotopic probe labeling kits

Michael Myers myersm at
Fri Oct 20 09:24:22 EST 1995

In article <Pine.SUN.3.91.951012104514.22484B-100000 at chuma>,
berryhil at CHUMA.CAS.USF.EDU ("Bridgette Berryhill ", BIO) wrote:

>I am in the process of choosing a non-isotopic labeling kit with which to 
>label a probe for library screening purposes.  I am considering the 
>Rad-Free system from Schleicher and Schuell.  Has anyone out there used 
>this kit and found success with it?  

I did a test southern blot w/ the RadFree kit and it looked very promising
in terms of sensitivity. The sensitivity test they recommend that you
perform (a dot blot w/ increasing amounts of plasmid DNA) also worked
quite well. A few aspects of the RadFree system are inconvenient:
1) very long blocking time
2) the substrate sheets -- S&S thinks they a plus, I think they're a pain.
If you have a non-standard size blot and try to cut the substrate sheet to
conserve it, more than likely you will end up with increased background
and a very messy looking autorad.
3) the substrate sheets are very expensive
4) you're supposed to do the incubation of filter + substrate sheet in an
exposure cassette prewarmed to 37 degrees. 

I didn't have the time to experiment further with the kit, but it looked
very promising.

Michael Myers
Laboratory of Genetics
The Rockefeller University
212-327-8233  (-7420 fax)
myersm at

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