Exposing southern gel to UV before transfer - (May/19/2006 )

I am comparing a number of southern tech. to the one we use in our lab.

I was wondering what are the advantages to exposing the gel to shortwave UV for 2-5 mins before setting up the transfer.

Thanks

just a hunch, but wouldn't it be like an extension of the denaturing wash?
wouldn't it just fractionate the DNA a bit more, so the transfer of smaller pieces to the membrane are that much more efficient?

I don't use that method, but I would guess this is what it is for