Easy DryTM are absorbent pads saturated with a sterile, dehydrated culture medium. Each pad is pre-plated in a Petri dish and is immediately ready to use after pouring sterile distilled or deionized water on it. Easy DryTM are optimal for the examination of large sample volumes by the membrane filter method.
Easy DryTM Chromatic Coli Coliform is a chromogenic selective medium used for the detection and enumeration of β-glucuronidase-positive E. coli and coliform bacteria in raw materials, water, waste water, beverages, foods and other products.
PREPARATION
1.
Cut open a bag and remove the number of Easy Dry plates needed.
2.
Moisten the pad contained
in the Petri dish with 2.2 ml of sterile distilled or deionized water.
3.
Wait 5 minutes before
using.
TEST PROCEDURE
Filter the sample through a filter membrane (0.45 μm pore diameter). Transfer the membrane onto a plate containing a just rehydrated pad. Incubation conditions may vary depending on the target of the analysis:
• 44 ± 1°C for 24 ± 2 hours if research is focused on fecal coliform bacteria;
• 30 ± 1°C for 24-48 hours to maximize total coliform detection.
INTERPRETING RESULTS
Examine the membrane for growth. Observe the color and the morphology of the colonies and interpret the results as indicated in the ID table.
ID Table
|
Microorganism |
Typical colony color |
|
E. coli* |
Green |
|
Other coliform bacteria |
Mauve |
|
Other
bacteria (if not
inhibited) |
Colourless |
*β-glucuronidase-negative E. coli strains, such as E. coli O157, are colorless on this medium.
APPEARANCE OF THE MEDIUM
Whitish pad. Yellowish once rehydrated.
STORAGE
Store at 10-25°C away from light. Do not
use the product beyond its expiry date on the label or if product shows any
evidence of contamination or any sign of deterioration.
SHELF LIFE
2 years.
