Gas-pak

Gas-pak

This is a method used in 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"). It is a much simpler technique than the McIntosh and Filde's anaerobic jar where one need to pump gases in and out.

There are commercially available, use-and-throw sachets containing a dry powder or pellets, which when mixed with water and kept in an appropriately sized airtight jar, produces and atmosphere free of elemental oxygen gas. These are used to produce an anaerobic cultures in Microbiology. [Textbook of Microbiology by Prof. C P Baveja, ISBN 81-7855-266-3] [extbook of Microbiology by Ananthanarayan and Panikar, ISBN 81-250-2808-0]

Constituents of gas-pak sachets

#Sodium borohydride - NaBH4
#Sodium bicarbonate - NaHCO3
#Citric acid - C3H5O(COOH)3
#Cobalt chloride - CoCl2 (catalyst)
....add water(H2O) to activate.

Reactions

*NaBH4 + 2 H2O = NaBO2 + 4 H2
*C3H5O(COOH)3 + 2 NaHCO3 + [CoCl2] = C3H5O(COONa)3 + 3 CO2 + 3 H2 + [CoCl2]
*2 H2 + O2 + [Catalyst] = 2 H2O + [Catalyst]

Consumption of oxygen

These chemicals react with water to produce hydrogen and carbon dioxide along with sodium citrate and water (C3H5O(COONa)3) as byproducts [http://en.wiktionary.org/wiki/byproduct] . Again, Hydrogen, in presence of oxygen and a catalyst like Palladiumised alumina(supplied separately), combines to form water.

Culture method

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

Indicator: Generally used chemical indicator for this purpose is "chemical methylene blue solution" that has never since synthesis been exposed to elemental oxygen. It is colorless and gets colored deep blue on oxidation in presence of atmospheric oxygen in the jar.

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Pak-Arab Refinery — (PARCO) is an oil refinery located in Mehmood Kot in Multan District, Punjab, Pakistan.In September 2000, Pak Arab Refinery largest capacity refinery of 100,000 barrels per day, costing US$ 886 million commissioned well within budget and a month… …   Wikipedia

  • Gas-to-Liquid — GtL Diesel Kurzbeschreibung Dieselkraftstoff Herkunft synthetisch Eigenschaften Aggregatzustand flüssig Cetanzahl 75 80 CZ …   Deutsch Wikipedia

  • Gas-to-Liquids — GtL Diesel Kurzbeschreibung Dieselkraftstoff Herkunft synthetisch Eigenschaften Aggregatzustand flüssig Cetanzahl 75 80 CZ …   Deutsch Wikipedia

  • Scott 2.2/ 3.5/ 4.5 Air-Pak SCBA — The Scott Air Pak SCBA is an open circuit, self contained breathing apparatus designed to meet the National Fire Protection Association (NFPA)Standard 1981. All components, excluding the air cylinder, have been designed and manufactured by Scott… …   Wikipedia

  • CS gas — IUPAC name …   Wikipedia

  • Iran–Pakistan–India gas pipeline — The Iran–Pakistan–India gas pipeline, also known as the IPI pipeline or the Peace pipeline, is a proposed convert|2775|km|mi|0|adj=on pipeline to deliver natural gas from Iran to Pakistan and India. Iran is interested to also include China to… …   Wikipedia

  • Pakistan — /pak euh stan , pah keuh stahn /, n. 1. Islamic Republic of, a republic in S Asia, between India and Afghanistan: formerly part of British India; known as West Pakistan from 1947 71 to distinguish it from East Pakistan (now Bangladesh).… …   Universalium

  • Disasters — ▪ 2009 Introduction Aviation       January 23, Poland. A Spanish built CASA transport plane carrying members of the Polish air force home from a conference on flight safety in Warsaw crashes near the town of Miroslawiec; all 20 aboard are killed …   Universalium

  • Dates of 2007 — ▪ 2008 January Ladies and gentlemen: on this day, at this hour, it is still within our power to shape the outcome of this battle. Let us find our resolve, and turn events toward victory. U.S. Pres. George W. Bush, asking for support for his… …   Universalium

  • Dates of 2008 — ▪ 2009 January As we meet tonight, our economy is undergoing a period of uncertainty.… At kitchen tables across our country, there is a concern about our economic future. U.S. Pres. George W. Bush, in his final state of the union address, January …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”