faulty southern hybridzation

[Julie Wilberding]

Hi,  I have posted on this before but I think I narrowed my problem to
possibly the hybridiztion step.  Does volume of hybridization solution play
a role?  My symptom on my autoradiograms is low signal plus low background.
 The signl is 4 to 5 fold lower than it should be.  I load 20 ug of DNA on
the gel and my photo is indicating that I have DNA in the gel.  I also do
not think transfer to the membrane is the problem.  I label my probe with
the Ambion random decamer labelling kit but I don't ever count after
labelling.  Any thoughts from any experts as to what the problem might
be????

Julie