Thioglycollate broth

Fluid thioglycollate media or thioglycollate broth is a multi-purpose enriched differentiating media used primarily to differentiate oxygen requirement levels of various organisms. Oxygen levels throughout the media are reduced via reaction with Sodium Thioglycolate. [http://ftp.ccccd.edu/dcain/CCCCD%20Micro/thioglycollatebroth.htm] This produces a range of oxygen levels in the media that decreases with increasing distance from the surface. This allows differentiation of aerobic, anaerobic, microaerophilic and facultatively anaerobic organisms based upon growth at various levels in the media. As an example, anaerobic "Clostridium" will be seen growing only in lower portions of the media. O₂ is often indicated in the media by a pink color change.

Sources

*http://ftp.ccccd.edu/dcain/CCCCD%20Micro/thioglycollatebroth.htm
*http://www.spectromelt.com/analytics/Micro_Manual/TEDISdata/prods/1_08191_0500_5000.html
*http://www.keul.de/english/products/microbiology_-_labm/media_range/fluid_thioglycollate_medium_(u.s.p._).html