I think several possibilities here:
1. Your DNA sample quality is not good. May be degraded before you do
restriction digestion. Have you check your DNA quality by running a simple
agarose before digestion?
2. Have you check your probe is a specific probe or the probe you are using
is your right probe?
3. How large is that smear? Is it possible there are two forms with similar
size hybridize by your probe?
More information is required as I don't know your probe, gel running
condition , probe size, DNA quality.
sokching <p12465 at PKPEL.CC.UKM.MY> wrote in message
news:126.96.36.199.19990326154500.0068b630 at pkpel.cc.ukm.my...
> I'm having problems with my southern blots. The probe is hybridizing to
> everything....therefore a smear appears on the autorad. As I'm using the
> ECL kit, the hybridization temperature cannot exceed 42C. I've tried
> increasing the stringency of the washing but it doesn't help. I'd
> appreciate any ideas. Thanks.