disappearing bands

Aaron Pawlyk aaron at netnews.upenn.edu
Mon Aug 8 20:39:39 EST 1994

Frederick Garbrecht (FRED at bmt.mcw.edu) wrote:
: When I visualize PCR products on agarose gels (0.5x TAE,  ethidium 
: bromide),  about 1 out of 10-15 of the gels has no bands, not even 
: the DNA marker ladder bands.  If I re-do the gel from scratch, 
: usually it looks OK (I get the expected bands).  Probably something 
: really stupid is going on, but I am baffled.  Anyone else have this 
: kind of dumb problem?

: Frederick C. Garbrecht
: fred at bmt.mcw.edu
: fgarbrec at post.its.mcw.edu
: Bone Marrow Transplant Program
: Medical College of Wisconsin
: phone 414 257 5053
: fax   414 257 7994

Hmmmm.  The first thing I wonder is if you forget to add EtBr if you are 
trying to visualize the gel with UV.  That could be it.

Another thing you may accidently be doing is reversing the electrodes when
you hook it up.  I always check my gel 10 minutes after I start them to make 
sure that the dye front is moving in the proper direction.

			-- Aaron

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