Hi evoldir I posted a comment last month asking for opinions on the recovery of high molecular weight DNA from tissues. Thanks very much to all who replied, and in particular Scott McCairns, Eric Parent, Diana Wolf and Tasha Belfiore. There is not much variation in the answers, which is a good sign. The following summary may be of use to readers: (1) The good old phenol:chloroform method never appears to disappoint. So that is one option. Can be coupled with ethanol or isopropanol precipitation for extra purity. Intriguingly however, the reason I wrote this posting originally is that we were getting a lot of degradation in our samples that were P:C purified. I now speculate that we must just have very crappy tissue, or some nasty nuclease contamination in our buffers. (2) A second option is the method reported by Aljanabi and Martinez, Nucleic Acids Research 25:4692-4693 (1997). Apparently can be of great use on a number of tissues. I have the pdf for anyone who would like it. (3) Lastly some useful info derived from Qiagen. Qiagen state that their filter based kits (and by inference other people's filter based kits) shear the DNA more than alcohol precipitation and spin methods. They recommend therefore the Gentra puregen kit that they sell. For USA users, these are sold by Fisher under the name Archivepure. As the method is based on a silica solution (as far as I can tell), I suspect one could also use the original protocol published by Boom et al (Rapid and Simple Method for Purification of Nucleic Acids, J Clin Microbiology 28:495-503 (1990)). Again I have the pdf if anyone wants it. Well thanks again to the respondents, and good luck to anyone out there after the big fragments. Tom Gilbert Dr Tom Gilbert Lektor/Associate Professor Institute for Biology University of Copenhagen Denmark mtpgilbert@gmail.com