piperidine background

[Yingyun Liu]

I am doing genomic footprinting with DMS and permangnate. The problem I have 
is that I always have high background bands of Gs with those naked DNA samples 
not treated with DMS or permangnate. I guess this is because the piperidine 
treatment. I treat the DNA samples with 1% piperidine in water for 10 minutes 
at 90 degree C. Could anybody out there offer me some advices to circumvent 
this problem? please email me at yxl22 at psu.edu. thanks. I appreciate it very 
much.   
yingyun