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.

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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

 

Learn 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 IDEXX’s 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 we have 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.

Because the Enterolert-DW Test is used with the Quanti-Tray system, any sterile vessel can be used.

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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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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Product Information

Enterolert-DW Test (20-test pack)
Catalogue Number: WENTDW-020

Enterolert-DW Test (200-test pack)
Catalogue Number: WENTDW-200

Snap pack and Quanti-Tray bundles are available.

Water Customer Support

Australia & New Zealand Head Office

IDEXX Laboratories Pty Ltd.
Unit 6, 38-46
South Street
Rydalmere, NSW 2116
AUSTRALIA

Phone (AUS): 1300 44 33 99
Phone (NZ): 0800 838 522

Fax (AU): 1800 634 409
Fax: (NZ): 0800 448 443

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