DNA from cartilage?

[wolffie at u.washington.edu]

I'm extracting DNA from cartilage for Southern blotting and PCR.

Lots of glycoprotein or other such white glop coprecipitates with the DNA.  

I don't know how much of a problem this is going to be, but I'd like to get  
rid of the stuff if I can.

Any ideas?

The cartilage is minced, digested with proteinase K in 1% SDS-STE (sometimes  
predigested with pronase or collagenase).  Then we add 1/3 vol of saturated  
NaCl and extract this with Chloroform/isoamyl alcohol and precipitate with  
isopropanol (we don't use phenol anymore).  The flocculent white precipitate  
doesn't look like DNA and is much larger than one would expect; although it  
does contain DNA, I expect this stuff is mostly digested glycoprotein  
matrix.

Thanks,
John Wolff,
University of Washington