Enterolert-DW
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.
- Confirmed results in 24 hours.
- Same easy-to-use platform as the Colilert-18 Test.
Overview
Easy
- Ready-to-use media.
- Simple procedure.
- Most Probable Number (MPN) enumeration.
- Unit-dosed packaging eliminates media preparation.
- Reagent contains no toxic compounds.
Rapid
- Confirmed results in 24 hours.
- Simplified quality control.
- Less than 1 minute of hands-on time.
Accurate
- More accurate when compared to ISO 7899-2 on all samples.
- More accurate when compared to Microbiology of Drinking Water (MoDW) part 5 methods, on chlorine-stressed samples.
- Liquid enrichment ensures optimised recovery.
- Eliminates subjective interpretation of results determined by traditional methods.
Science
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 utilises ortho-nitrophenyl-β-D-glucoside as a nutrient indicator and incorporates a specifically designed blue background colour in its formulation. When the enzyme substrate is metabolised by enterococci, the sample turns from blue to green to indicate detection. Any change from the original colour to green is considered a positive result. No ultraviolet light source is required.
How to use
How to use the Enterolert-DW Test
Quantification
Step 1
Add reagent to sample. Cap vessel and shake to mix.
Step 2
Add sample reagent to Quanti-Tray (counts from 1–200) or Quanti-Tray/2000 (counts from 1–2,419).
Step 3
Seal using Quanti-Tray Sealer and incubate for 24 hours at 41°C ± 0.5°C.
Step 4
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 the IDEXX proprietary Defined Substrate Technology (DST). The Enterolert-DW Test utilises ortho-nitrophenyl-ß-D-glucoside as a nutrient indicator and incorporates a specifically designed blue background colour in its formulation. When the enzyme substrate is metabolised by the enterococci, the sample turns from blue to green to indicate a positive detection. Any change from the original colour 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 detected in trials and studies are:
Enterococcus faecalis
Enterococcus faecium
Enterococcus hirae
Enterococcus gallinarum
Enterococcus casseliflavus
Enterococcus durans
Enterococcus avium
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 colour is a valid negative test; a green colour 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 metabolised by the enterococci, the sample turns from blue to green to indicate a positive result. Any change from the original colour 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 colour with a slight greenish tint; it should be dry and free-flowing. Any concerns about the colour or integrity of the reagent powder should be directed to IDEXX Technical Support.
Resources & Tools
Tests & Accessories
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Product Information
Enterolert-DW Test (20-test pack)
Product Number: 98-18072-00
Catalogue Number: WENTDW-020
Enterolert-DW Test (200-test pack)
Product Number: 98-18074-00
Catalogue Number: WENTDW-200
IDEXX-QC Enterococci Drinking Water Kit
Product Number: 98-29003-02
Catalogue Number: WQC-ENTDW
Snap pack and Quanti-Tray combination packs are also available.
Resources
IDEXX Water has reference materials and approval documents to support the many products in our water portfolio. Find the document(s) you need by selecting the link below.
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