Smeared footprints

[kathy gately]

I'm using a footprinting method, adapted from that of Galas and Schmitz
and I'm getting alot of background smearing in the lanes containing the
footprints. Any ideas?
I was also wondering if anyone could recommend a good method/column for
probe purification? I'm digesting my probe with restrictions enzymes
that give a 3' end and a 5' end, then I 5' end-label with P32, I would
like a method of purification that would result in the probe being
eluted in a small final volume.
Thanks for any advice, kathy.