multiple bands

[Ann M. Yezerski]

I need any and all suggestions for getting rid of multiple banding 
patterns on a PCR.  Many I'm sure I've tried, but I need some fresh 
ideas.  I using Kocher et al.'s universal 12S primers on lizard 
extracts.   My best results have come from a ramped 45 degree anneal for 
one minute, and all other periods also for one minute.  Generally I use 1 
microliter of MgCl2 per 50 microliter reaction.  My results 
produce one, two, or all of the following sized bands:378 (the right one), 
approx. 150, and approx 50!  

If you any suggestions, write to me at ayezersk at moose.uvm.edu

Thanks.