IUBio

Durham tubes and how do they work

richard richardz at cy-net.net
Thu Jan 23 11:12:17 EST 1997


In article <5c6elb$ptg at juliana.sprynet.com>, hsamander at sprynet.com says:
>
>>   PRODEV1A <PRODEV1A at fox.nstn.ca> writes:
>>  I would like to know more about "Durham Tubes And how they work??"
>>  
>>  
>>>>>
>In response to your question, a Durham tube is a test tube that contains an inverted vial..the formation of a bubble within this 
>vial reveal gas production by the microbe being tested.  For example, "the fermentation of sugars by microorganisms is 
>accompanied by the formation of either acid or acid and gas;  the presence of the acid is detected by a pH indicator in the 
>medium.  [this works for sugar fermentation tests]  If you are testing for sugar, the medium will turn from red to yellow.  Again, 
>gas production is determined by whether or not there is bubble formation within the vial.
>
>        Many biochemical tests are done using test tubes, however in well-developed labs there are easier ways to do 
>biochemical tests.  However, a few that can be done using test tubes are: mixed acid fermentation tests, Voges-Proskauer 
>tests..these are biooxidation testing.   
>
>I hope that is helpful to you..try reading a few lab manuals that discuss testing for pathogenic organisms..they will have
>more extensive explainations!!!

Gadgets such as API and Micro ID and Enterotubes, and discs impregnated
with 'whatever substrate' are all relatively new --25-30 years ago
the inverted little tube was as common in the lab. as the petri plate.

For some types of work they are still the best way to go.



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