توضیحات
Colizist is a selective and enrichment kit for simultaneous identification of E. coli and coliforms. An easy and reliable method for rapid identification of E. coli and total coliforms in water, with an accuracy equivalent to identifying a target bacterium among 1 million heterotrophic bacteria in 100 ml of water sample. It has chromogenic and fluorescence substrates that, based on the enzymatic processes of the target bacteria, convert this medium into a powerful and accurate tool for the identification of the target bacteria from the sample.
“Coizist™ is a cost-effective product in terms of time and cost, because:”
- The method for using Coizist™ takes less than 1 minute.
- Coizist™ is based on EPA-approved methods.
- Coizist™ can be 20% to 70% cheaper than traditional methods.
- The Coizist™ simultaneously detects E. coli and Coliforms in water. The blue color in the sample is the result of X-gal metabolism by the coliforms and the fluorescent color is caused by the metabolism of MUG by E. coli. Coizist™ is able to detect one coliform (CFU 1) in 100 mL sample containing more than two million heterotrophic bacteria within 18-24 hours. This kit also contains growth inhibitors for Aeromonas and Pseudomonas.
Storage conditions: Store at 25-2 degrees Celsius and away from light. Storage at lower temperatures can lead to a longer product shelf life.
Test
Test
Inoculation
Open the lid of the Coizist™ bottle under sterile conditions and add 100 milliliters of the water sample to it.
Note: If the water sample is chlorinated, add 100 microliters of 3% sodium thiosulfate to the sample and shake well for about 15 seconds. Place the bottle in a 35-degree Celsius incubator for 24-16 hours to incubate the sample, then examine the results.
If the samples are kept at a temperature of about 25 degrees Celsius, the test should be performed within a maximum of 6 hours. Under specific condition, samples can be stored at 2-8 degrees Celsius for up to 24 hours.
If the samples are incubated at 25-20°C, the incubation time should be increased up to 48 hours.
Close the cap tightly and shake well to dissolve the materials in the bottle.
Incubate the inoculated kit at a temperature of 35 ± 2 degrees Celsius for 18-24 hours.
Notes
- If the water sample has a color, the inoculated sample with Coizist™ should be compared with a control sample from the same water source.
- Coizist™ is used for primary tests of water samples and is not recommended for use with concentrated or enriched samples.
- If samples with high levels of chlorine are added to Coizist™, a blue color radiation may be observed. In case of such a situation, the sample is considered invalid and the test should be stopped.
- Working with Coizist™ should be performed under sterile conditions and in accordance with GLP principles.
results interpretation
- Negative result: no color change is observed in the culture medium and the color of the medium remains yellow.
Sometimes, the bacteria in the original sample may have been subjected to stressful conditions and have undergone genetic changes. In this case, some bacterial specific enzymes may be deactivated for the X-gal and MUG reaction, and the color change of the medium may not be observed with fluorescence, and false negative results may be obtained. In this case, the yellowness of the medium after 24 hours does not definitely indicate the absence of bacteria. To ensure the correctness of the results, the indole test must be performed after 24 hours on the yellow media.
- Total coliforms: Any change in the color of the environment from yellow to green-blue that does not disappear by shaking the kit, even in the upper parts of the kit, indicates the presence of coliforms in the sample and the X-gal reaction.
- E. coli: Expose the discolored samples to UV light. In a dark environment, shine a six-watt UV lamp with a wavelength of 366 nm on the sample from a distance of 3-4 cm and observe the results. Pale blue fluorescence indicates the presence of E. coli bacteria in the sample and MUG reaction.
Warning: Avoid direct exposure of UV light to eyes and samples.
|
Indole Reaction |
Fluorescence |
Color Change to Green-Blue |
Growth |
ATCC |
Microorganism |
|
-
|
-
|
+
|
+
|
11775
|
E. coli
|
|
+
|
+
|
+
|
+
|
25922
|
E. coli
|
|
-
|
-
|
+
|
+
|
|
Total coliforms
|
|
-
|
-
|
-
|
+
|
14028
|
Salmonella typhimurium
|
|
-
|
-
|
-
|
+
|
11060
|
Shigella Sonnei
|
