Gas-pak

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This table displays the steps involved in using a GasPak to create a completely anaerobic environment for incubating an inoculated agar plate. After inoculating the agar plate(s) with bacteria under aseptic conditions, the agar plates are placed in an anaerobic jar that contains components, like the catalyst chamber, that will help facilitate the reaction to eliminate free oxygen and provide completely anaerobic conditions. The methylene blue strip is an indicator that is placed in the jar that will turn colorless under entirely anaerobic conditions, which provides proof that the jar was able to successfully reach an anaerobic state. The components of the GasPak envelope along with the addition of water, allow for the start of the reaction that takes place in the catalyst chamber. The sealed anaerobic jar is then incubated at a desired temperature to allow growth of the bacteria. In the above figure for example, the incubation occurred at 100deg Fahrenheit. A colorless indicator strip provides proof that the anaerobic conditions were met and the agar plates can now be observed for bacterial growth. Gas Pak.png
This table displays the steps involved in using a GasPak to create a completely anaerobic environment for incubating an inoculated agar plate. After inoculating the agar plate(s) with bacteria under aseptic conditions, the agar plates are placed in an anaerobic jar that contains components, like the catalyst chamber, that will help facilitate the reaction to eliminate free oxygen and provide completely anaerobic conditions. The methylene blue strip is an indicator that is placed in the jar that will turn colorless under entirely anaerobic conditions, which provides proof that the jar was able to successfully reach an anaerobic state. The components of the GasPak envelope along with the addition of water, allow for the start of the reaction that takes place in the catalyst chamber. The sealed anaerobic jar is then incubated at a desired temperature to allow growth of the bacteria. In the above figure for example, the incubation occurred at 100° Fahrenheit. A colorless indicator strip provides proof that the anaerobic conditions were met and the agar plates can now be observed for bacterial growth.

Gas-pak is a method used in the production of an anaerobic environment. It is used to culture bacteria which die or fail to grow in the presence of oxygen ( anaerobes ).

Contents

These are commercially available, disposable sachets containing a dry powder or pellets, which, when mixed with water and kept in an appropriately sized airtight jar, produce an atmosphere free of elemental oxygen gas (O2). They are used to produce an anaerobic culture in microbiology. [2] [3] [4] It is a much simpler technique than the McIntosh and Filde's anaerobic jar where one needs to pump gases in and out.

Constituents of gas-pak sachets

  1. Sodium borohydride - NaBH4
  2. Sodium bicarbonate - NaHCO3
  3. Citric acid - C3H5O(COOH)3
  4. Cobalt chloride - CoCl2 (catalyst)

The addition of a Dicot Catalyst may be required to initiate the reaction.

Reactions

Consumption of oxygen

These chemicals react with water to produce hydrogen and carbon dioxide along with sodium citrate (C3H5O(COONa)3) and water as byproducts . Again, hydrogen and oxygen reacting on a catalyst like Palladiumised alumina (supplied separately) combine to form water.

Culture method

The medium, the gas-pak sachet (opened and with water added) and an indicator are placed in an air-tight gas jar which is incubated at the desired temperature. The indicator tells whether the environment was indeed oxygen free or not.

The chemical indicator generally used for this purpose is "chemical methylene blue solution" that since synthesis has never been exposed to elemental oxygen. It is colored deep blue on oxidation in presence of atmospheric oxygen in the jar, but will become colorless when oxygen is gone, and anaerobic conditions are achieved.

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Chlorine Chemical element with atomic number 17

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Carboxylic acid oxoacid having the structure RC(=O)OH, used as a suffix in systematic name formation to denote the –C(=O)OH group including its carbon atom

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Sodium carbonate chemical compound

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Sodium hypochlorite Chemical compound

Sodium hypochlorite is a chemical compound with the formula NaOCl or NaClO, comprising a sodium cation and a hypochlorite anion. It may also be viewed as the sodium salt of hypochlorous acid. The anhydrous compound is unstable and may decompose explosively. It can be crystallized as a pentahydrate NaOCl·5H
2O, a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated.

Chlorine dioxide chemical compound

Chlorine dioxide is a chemical compound with the formula ClO2 that exists as yellowish-green gas above 11 °C, a reddish-brown liquid between −59 °C and 11 °C, and as bright orange crystals when colder. It is an oxidizing agent, able to transfer oxygen to a variety of substrates, while gaining one or more electrons via oxidation-reduction (redox). It does not hydrolyze when it enters water, and is usually handled as a dissolved gas in solution in water. Potential hazards with chlorine dioxide include health concerns, explosiveness and fire ignition. It is commonly used as a bleach.

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Sodium acetate chemical compound

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Compounds of oxygen any chemical compound having at least one oxygen atom

The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: −​1⁄2 (superoxides), −​1⁄3 (ozonides), 0, +​1⁄2 (dioxygenyl), +1, and +2.

McIntosh and Filde's 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).

Sodium bisulfite chemical compound

Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO3. Sodium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions. It is a white solid with an odor of sulfur dioxide. Regardless of its ill-defined nature, "sodium bisulfite" is a food additive with E number E222.

Dry ice color show

Dry ice color show is the formation of carbonic acid (H2CO3) by the reaction of dry ice, the solid form of carbon dioxide (CO2), and water. The reaction between these 2 compounds lower the pH of the solution, therefore making the solution more acidic. Dry ice has a temperature of –78.5 °C (-109.3°F)and normally exist in gas state. By applying universal indicator to the solution, the changing of the pH can be indicated as the color of the solution changes into the contrast color. This experiment is usually conducted as a classroom demonstration of pH and properties of carbon dioxide since the materials required are handful and can be prepared easily. Solid carbon dioxide can cause frostbite when in contact with the skin, by sticking to the moist tissue, such as wet skin or tongue. Solid carbon dioxide undergoes sublimation upon exposure to air. This means it transforms directly from the solid phase to the gaseous phase without melting into liquid.

References

  1. ↑ "GasPak System (The Anaerobic jar)". Medical Laboratories. Retrieved 2016-12-03.
  2. ↑ Textbook of Microbiology by Prof. C P Baveja, ISBN   81-7855-266-3
  3. ↑ Textbook of Microbiology by Ananthanarayan and Panikar, ISBN   81-250-2808-0
  4. ↑ "Archived copy". Archived from the original on 2009-09-28. Retrieved 2009-10-27.CS1 maint: archived copy as title (link) "GasPak System". Accessed October 27, 2009.
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