Southerns/nylon membranes

[Jun Ishikawa]

Dear Roy,

> In the past I have used nytran and prehybed and hyb'd in 6x SSC and 1% SDS,
> no denhards or Salmon sperm DNA. I never had any problem with background.
> Lately, I have started doing southerns in a glass tube, in a rotating
> hybridization oven. I have switched over to zetaprobe and .25M NaPO4 and
> 7% SDS. Results have been generally very bad. Pinhead type spotting is
> a bad problem. 

> 3. Different nylon membranes. Are some less suited for 7% SDS solutions?

I'm using Hybond-N+ (Amersham). The membrane seems to work well. 
No problem.

Good luck!