Detects enterococci in drinking water
The Enterolert-DW Test, coupled with the Quanti-Tray system, provides:
- More accurate and specific compared to ISO 7899-2 and MoDW 2006, part 5.
- Confirmed results in 24 hours.
- Same easy-to-use platform as the Colilert-18 Test.
- Ready-to-use media.
- Simple procedure.
- Most Probable Number (MPN) enumeration.
- Unit-dosed packaging eliminates media preparation.
- Reagent contains no toxic compounds.
- Confirmed results in 24 hours.
- Simplified quality control.
- Less than 1 minute of hands-on time.
- More accurate when compared to ISO 7899-2 on all samples.
- More accurate when compared to Microbiology of Drinking Water (MoDW) 2006, part 5, on chlorine-stressed samples.
- Liquid enrichment ensures optimized recovery.
- Eliminates subjective interpretation of results determined by traditional methods.
How the Enterolert-DW Test works
The Enterolert-DW Test uses a Defined Substrate Technology (DST) nutrient indicator to detect enterococci. When coupled with the IDEXX Quanti-Tray System, the Enterolert-DW Test provides quantitative confirmed results in 24 hours. The Enterolert-DW Test utilizes ortho-nitrophenyl-β-D-glucoside as a nutrient indicator and incorporates a specifically designed blue background color in its formulation. When the enzyme substrate is metabolized by enterococci, the sample turns from blue to green to indicate detection. Any change from the original color to green is considered a positive result. No ultraviolet light source is required.
How to use
Learn how to use the Enterolert-DW Test
Add reagent to sample. Cap vessel and shake to mix.
Add sample reagent to Quanti-Tray (counts from 1–200) or Quanti-Tray/2000 (counts from 1–2,419).
Seal using Quanti-Tray Sealer and incubate for 24 hours at 41°C ± 0.5°C.
Count positive wells and refer to most probable number (MPN) table.
Frequently asked questions
The Enterolert-DW Test is designed to detect Enterococcusspecies in drinking water samples. It is based on IDEXX’s proprietary Defined Substrate Technology (DST). The Enterolert-DW Test utilizes ortho-nitrophenyl-ß-D-glucoside as a nutrient indicator and incorporates a specifically designed blue background color in its formulation. When the enzyme substrate is metabolized by the enterococci, the sample turns from blue to green to indicate a positive detection. Any change from the original color to green is considered a positive result. No ultraviolet light source is required.
The Enterolert-DW Test is designed to detect enterococci in drinking water. As with any microbial method, some Enterococcus species are more easily detected than others. Some examples of Enterococcus species we have detected in trials and studies are:
There is no comparator for the Enterolert-DW Test. For comparison, use a negative control when interpreting results.
The Enterolert-DW Test is incubated at 41°C ± 0.5°C for 24 hours and the results are valid up to 28 hours, unless your local regulations indicate differently.
Yes, if they are positive. An inoculated Enterolert-DW Test sample that is positive for enterococci before 24 hours is a confirmed positive test for enterococci.
Yes, if they are negative. If an inoculated Enterolert-DW Test sample is inadvertently incubated over 28 hours, lack of green color is a valid negative test; a green color after the 28 hours is not valid and should be repeated or verified.
Yes, both the Quanti-Tray and Quanti-Tray/2000 can be used with the Enterolert-DW Test.
Because the Enterolert-DW Test is used with the Quanti-Tray system, any sterile vessel can be used.
Store the Enterolert-DW Test at 2–25°C, away from direct light and humidity.
When the enzyme substrate is metabolized by the enterococci, the sample turns from blue to green to indicate a positive result. Any change from the original color to green is considered a positive result.
The Enterolert-DW Test is designed specifically for drinking water testing. Extensive studies were performed on enterococci stressed by chlorine, to mimic the impact of water treatment.
The Enterolert-DW Test may be used for other water types. Before implementing testing, IDEXX recommends you use a typical laboratory validation protocol to assure that any other water types will work with this product before implementation.
The Enterolert-DW reagent powder should be white to off-white in color with a slight greenish tint; it should be dry and free-flowing. Any concerns about the color or integrity of the reagent powder should be directed to IDEXX Technical Support.
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Enterolert-DW Test (20-test pack)
Catalog Number: WENTDW-020
Enterolert-DW Test (200-test pack)
Catalog Number: WENTDW-200
Snap pack and Quanti-Tray bundles are available.
Water Customer Support
IDEXX Laboratories, Inc.
One IDEXX Drive
Westbrook, Maine 04092 USA
*The Enterolert-DW Test is intended to be used only for water quality research and analysis, by technically qualified individuals or under their supervision.