I've noticed this thread of "background" on Southerns cropping up again.
I'd like to toss my $0.02 worth. About 6 years ago I was handed a
GeneScreen manual that stated that background could be minimized by
increasing the SDS concenctration to > 0.5%, and if taken to 1-2% the
normal inclusion of salmon sperm DNA could be eliminated. In my hands,
this has worked very well over the years. I routinely do my southerns in
1% SDS w/o SS-DNA. For me, this has been a cure (almost all the time)
for background and a money saver not having to buy SS-DNA.
As far as northerns go - can't recommend Virca et al Biotechniques
8:370 *enough*. With 5% SDS and a very efficient transfer, this protocol
has been like gold in our lab.
Hope this helps.
+ David L. Haviland, Ph.D. .***. .***. .***. +
+ Washington Univ. School of Med * | | | * * | | | * | | | * +
+ Dept. of Peds./Pulm. Box 8116 *| | | * * | | | * * | | | * +
+ One Children's Place * | | | * | | | * * | | | * +
+ St. Louis, MO 63110 '***' '***' '***' +
+ Internet:"haviland at kids.wustl.edu" +
+ Voice: 314-454-6076 FAX: 314-454-6076 +