HELP! DNA from foetal tissue

[frances at matai.vuw.ac.nz]

I have tried to extract high molecular weight DNA from a foetal tissue with no
success.  The DNA I get has degraded into two bands between 1 and 2 kb in
length.  I am using a standard proteinase K digestion followed by
phenol/chloroform extraction.  I am chopping up the tissue with a scalpel
blade proir to incubation overnight at 37oC.

I received the sample frozen and it was shipped on ice, but I don't know how it
was stored before that.  Refrigerated I imagine.

If anyone has done this sort of extraction before and has some tips I'd be most
grateful to hear from you.


Cheers

Frances