LaMotte EZ 3-0034 - Manual (Page 2)

• Ensure a safe field-testing experience by using the following: safety glasses for
each student, clean pail or bucket for washing hands, jug of clean water for
washing hands, soap (biodegradable if possible), towels, protective gloves, eye
wash bottle, first aid kit.
• Keep used Petri dishes taped shut and out of the reach of small children and
animals.
• Use one of the recommended disposal methods in procedure.
Coliscan Easygel EZ Method
In order for coliforms to ferment lactose, they must produce certain enzymes, which
can be identified and used to verify the presence of coliforms and E. coli. General
coliforms produce the enzyme galactosidase from lactose fermentation whereas, E.
coli produces the enzyme glucuronidase, in addition to galactosidase Coliscan
Easygel incorporates two special chromogenic substrates, which are acted upon by
the enzymes galactosidase and glucuronidase, to produce pigments of different
colors. General coliforms will produce the enzyme galactosidase and the colonies
that will grow will be a pink color. E. coli will produce galactosidase and
glucuronidase, and will grow as blue/purple colonies. The sum of the E. coli and
general coliforms is the total coliform number.
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Col lecting a Wa ter Sam ple
1. Remove the cap of a collection bottle. Do not touch the neck of the bottle or the
inside of the cap.
2. If you are testing stream water, face upstream while holding the bottle 5 to 6
inches below the surface.
3. When the bottle has filled, replace the cap.
4. The test can be done at the site or water samples may be collected in the sterile
collection bottle and transported back to the testing site. Water samples kept for
more than one hour before testing should be kept on ice or refrigerated.
5. Do not reuse the sample collection bottle.
Pro ce dure
1. Use a permanent marker or wax pencil to label a Petri
dish and a bottle of Coliscan Easygel with the sample
information. Tape the dish shut with two pieces of clear
tape. Use one piece of tape as the hinge and the other
as a latch.
2. Unwrap a sterile dropper. Handle the
dropper by the bulb end. Do not touch
the tip of the dropper with anything but
the water sample.
3. Thoroughly mix the water sample. Squeeze the bulb of the dropper. Insert the tip
of the dropper 2 – 3 inches below the surface of the water. Slowly release the
Smaller diameter
Contains Clear
Media Film
Lid
Bottom
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