Anyway to lyse bacteria but do not lyse WBC? - in human blood samples (Dec/22/2007 )

I am working on diagnosis of bacteremia.Is there anyway to lyse bacteria ,without lysing the WBC? or is there anyway to selectively remove WBC from the blood samples as I only interested in the DNA extraction of bacteria in the blood...

Thanks

-Sean0918-

QUOTE (Sean0918 @ Dec 22 2007, 07:56 PM)

Spin it at low speed only, like 150g 5-10 min or just let it settle by gravity?

-genehunter-1-

QUOTE (Sean0918 @ Dec 23 2007, 01:56 PM)

You could try a density gradient like Ficoll, assuming the denisty of the WBC and bacteria are sufficiently different.

-swanny-