McIntosh and Filde's anaerobic jar is an instrument used in the production of an anaerobic environment. This method of anaerorbiosis as others is used to culture bacteria which die or fail to grow in presence of oxygen (anaerobes).

Construction

The jar, about 20″×12.5″ is made up of a metal. Its parts are as follows:

1. The body made up of metal
   Metal
   A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
   
    (airtight)
2. The lid, also metal can be placed in an airtight fashion
3. A screw
   Screw
   A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...
   
    going through a curved metal strip to secure and hold the lid in place
4. A thermometer
   Thermometer
   Developed during the 16th and 17th centuries, a thermometer is a device that measures temperature or temperature gradient using a variety of different principles. A thermometer has two important elements: the temperature sensor Developed during the 16th and 17th centuries, a thermometer (from the...
   
    to measuring the internal temperature
5. A pressure gauge to measuring the internal pressure (or a side tube is attached to a manometer
6. Another side tube for evacuation and introduction of gases (to a gas cylinder or a vacuum pump
   Vacuum pump
   A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke.- Types :Pumps can be broadly categorized according to three techniques:...
   
   )
7. A wire cage hanging from the lid to hold a catalyst that makes hydrogen react to oxygen without the need of any ignition
   Combustion
   Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
   
    source

Method of use

• First:

1. The culture: The culture media are placed in side the jar, stacked up one on the other, and
2. Indicator
   Indicator
   Indicator may mean:In chemistry:* pH indicator, a chemical detector for protons in acid-base titrations* Redox indicator, a chemical detector for redox titrations* Complexometric indicator, a chemical detector for metal ions in complexometric titrations...
   
    system: Pseudomonas aeruginosa
   Pseudomonas aeruginosa
   Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...
   
   , inoculated on to a nutrient agar
   Nutrient agar
   Nutrient agar is a microbiological growth medium commonly used for the routine cultivation of non-fastidious bacteria. It is useful because it remains solid even at relatively high temperatures. Also, bacteria grown in nutrient agar grows on the surface, and is clearly visible as small colonies...
   
    plate is kept inside the jar along with the other plates. This bacteria need oxygen to grow (aerobic
   Aerobic organism
   An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
   
   ). A growth free culture plate at the end of the process indicates a successful anaerobiosis.

• Second:

⁶/₇^ths of the air inside is pumped out and replaced with either unmixed Hydrogen or as a 10%CO₂+90%H₂ mixture. The catalyst (Palladium

Palladium

Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...

) acts and the oxygen is used up in forming water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 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 atmospheric pressure

Atmospheric pressure

Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...

. The jar is now incubated at desired temperature settings.