Detaching Biofilms - Sonication? (May/01/2009 )

Hi Everyone !

I need to detach a biofilm from a surface which will then be processed to extract DNA. I am just wondering if sonication will be enought to remove all attached bacteria. The surface the biofilm will be attached to is a thin clay tablet. Any ideas?

Cheers

Why not remove it with a tool - like a sterile spatula?

GeorgeWolff on May 1 2009, 11:51 PM said:

I believe that removing it with a sterile spatula would still perhaps leave bacteria attached to the surface. In very thin biofilms, on the other hand, I guess it would not work (¿?).

I would include a sample of the clay tablet in the lysis reaction. Chemistry will remove things that mechanical disruption will not. A phenol/chloroform extraction would likely remove most anything organic.

phage434 on May 2 2009, 02:30 PM said:

thanks for your reply. should the phenol/chloroform extraction of the biofilm interfere with subsequent DNA extraction from it using e.g., a DNA isolation kit?

cheers

i would go with georgewolff's method of using a spatula to scrap the biofilm out. It should get like most of the thing. even if it's a thin biofilm u will still get something. It's kinda like u know scraping bacteria off agar plate. the more distance u scrap the "thicker" the cell mass get. Same theory .

I've read of scraping with a spatula, but in my protocol, we sonicate in a water bath. You place a steel tray inside the water bath and the plate inside the dry tray. the vibrations from the water transfer through the tray to the plate, causing the bacteria to loosen.

I just got an email from MoBio about their new kit:
http://www.mobio.com/pages/biofilm.html
I don't do biofilms, so I didn't look into it, but maybe it has some suggestions.