Black DNA from earthworms

[sjames at miu.edu]

I would like to know if anyone has encountered a similar phenomenon with 
other critters.  When we do any of several standard DNA preps, we get a 
very dark brown to black pellet that turns out to be DNA- it looks like 
DNA to UV, it does ok when we try to amplify various genes, etc.  Why the 
concern if it works?  It doesn't always work. Some worms yield darker DNA 
than others, and there have been problems getting PCR reactions to go.  
Magnesium manipulation sometimes helps, sometimes not.
   It would be nice to know 1) what is this dark stuff, 2) how to get rid 
of it, or 3) how to consistently work around it.  Yes, we have taken the 
dirt out of the worms first.  Thanks to all, and I hope this is not a FAQ.

Sam James  515-472-1146  fax:515-472-1167    sjames at miu.edu