DNA extraction

[Zhongtang Yu]

Hello netters!
	Help.
	I have been trying to extract the DNA from a aquifer directly. I  
have tried a few procedures but I failed because the aquifer contains only  
10e4 to 10e5 bacteria/gram of aquifer.  Anybody has successful experience  
to get DNA from aquifer containing low # of bacteria? 
	Also I am trying to extract the DNA from a biological activated  
carbon(BAC).  The BAC has many many bacteria but because of the adsorption  
of DNA onto the activated carbon I got a very low yield. Any effective way  
to desorb DNA from activated carbon?
	Thanks.

Zhongtang Yu
Dept. of Biol. 
New Mexico State Uniov.
La Cruces, NM 88003