Explain colonies

Gordon Reynolds gordonr at computek.net
Sat Aug 30 17:38:28 EST 1997


Colonies are visible clumps of bacteria all originating from a single 
motheerr cell, therefore they are genetically identical---a clone of 
bacteria.  You grow the colonies on a solid agar medium poured and 
solidi8fied in a petri dish.  Each colony repreesents one cell which ended 
up at that location on the agar plate.  A coliform is a gram negative rod 
bacterium which ferments lactose, and is a fecal organism, e.g. E. coli.
When E. coli is grown on a particular agar medium called EMB, the colony 
turns dark purple when using the lactose in the medium, turning a 
purple-green when reflected light hits it.  A stero microscope would 
enable you to see the colonies betteer, but you can see them with the 
naked eye, as well as counting the colonies.

In article <872089968.27797 at dejanews.com>, VEIUSA at aol.com says...
>
>I am doing some research and would like an explanation on what colonies
>are and how they are counted, processed, picked etc..  Also what is a
>coliform and green sheen???  WOuld I use a stereo microscope to perform
>any of these activities???  Appreciate any feedback.  Thx in advance!
>
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