View source for Organization:McIntosh and Fildes' anaerobic jar

{{Infobox laboratory equipment
|name         = McIntosh and Fildes' anaerobic jar
|image        = File:McIntosh and Fildes’ Anaerobic Jar.jpg
|caption      = 
|acronym      = 
|other_names  = 
|uses         = Production of an anaerobic environment
|notable_experiments = 
|inventor     = Paul Fildes and  James McIntosh
|manufacturer = 
|model        = 
|material     = 
|components   = 
|related      = 
}}

'''McIntosh and Fildes' anaerobic jar''' is an instrument used in the production of an anaerobic environment. This method of ''anaerobiosis'' as others is used to culture bacteria which die or fail to grow in presence of oxygen (''anaerobes'').<ref>Textbook of Microbiology by Prof. C P Baveja, {{ISBN|81-7855-266-3}}</ref><ref>Textbook of Microbiology by Ananthanarayan and Panikar, {{ISBN|81-250-2808-0}}</ref> It was originally introduced by James McIntosh, Paul Fildes and William Bulloch in 1916.<ref>{{Cite journal |last1=Mcintosh |first1=James |last2=Fildes |first2=Paul |last3=Bulloch |first3=William |date=1916 |title=A new apparatus for the isolation ans cultivation of anaerobic microorganisms. |url=http://dx.doi.org/10.1016/s0140-6736(01)11835-0 |journal=The Lancet |volume=187 |issue=4832 |pages=768–770 |doi=10.1016/s0140-6736(01)11835-0 |issn=0140-6736}}</ref> McIntosh and Fildes, after whom the device has been named, published an improved version in 1921.<ref>{{Cite journal |last1=McIntosh |first1=John |last2=Fildes |first2=Paul |date=31 March 1921 |title=An Improved Form of McIntosh and Fildes' Anaërobic Jar |journal=British Journal of Experimental Pathology |volume=2 |issue=3 |pages=153–154|pmc=2047683 }}</ref>

==Construction==
The jar, about {{convert|20|x|12.5|in}} is made of metal. Its parts are as follows:
#The body made up of [[Chemistry:Metal|metal]] (airtight)
#The lid, also metal can be placed in an airtight fashion
#A [[Engineering:Screw|screw]] going through a curved metal strip to secure and hold the lid in place
#A [[Physics:Thermometer|thermometer]] to measuring the internal temperature
#A pressure gauge to measuring the internal pressure (or a side tube is attached to a manometer)
# Another side tube for evacuation and introduction of gases (to a gas cylinder or a [[Physics:Vacuum pump|vacuum pump]])
#A wire cage hanging from the lid to hold a [[Chemistry:Catalyst|catalyst]] that makes hydrogen react to oxygen without the need of any [[Physics:Combustion|ignition]] source

==Method of use==
*First:
#'''The culture''': The culture media are placed inside the jar, stacked up one on the other, and
#'''[[Biology:Indicator organism|Indicator]] system''': ''[[Biology:Pseudomonas aeruginosa|Pseudomonas aeruginosa]]'', inoculated on to a nutrient agar plate is kept inside the jar along with the other plates. This bacteria need oxygen to grow (''[[Biology:Aerobic organism|aerobic]]''). A growth free culture plate at the end of the   process indicates a successful anaerobiosis.  However, ''P. aeruginosa'' possesses a denitrification pathway. If nitrate is present in the media, ''P. aeruginosa'' may still grow under anaerobic conditions.

*Second: <sup>6</sup>/<sub>7</sub><sup>ths</sup> of the air inside is pumped out and replaced with either unmixed Hydrogen or as a 10%CO<sub>2</sub>+90%H<sub>2</sub> mixture. The catalyst ([[Chemistry:Palladium|Palladium]]) acts and the oxygen is used up in forming [[Chemistry:Water|water]] with the hydrogen. The manometer registers this as a fall in the internal pressure of the jar.

*Third: Hydrogen is pumped in to fill up the jar so that the pressure inside equals [[Physics:Atmospheric pressure|atmospheric pressure]]. The jar is now incubated at desired temperature settings.

==References==
{{reflist}}
[[Category:Laboratory equipment]]
[[Category:Microbiology terms]]

{{Sourceattribution|McIntosh and Fildes' anaerobic jar}}