H2O news
August 2012 Issue
IDEXX Colilert-18/Quanti-Tray Test
IDEXX Colilert-18/Quanti-Tray Test

IDEXX announces that its Colilert®-18/Quanti-Tray® test becomes the new International Organization for Standardization (ISO) worldwide standard for detecting total coliforms and E. coli in water. The Organization has withdrawn ISO 9308-2:1990, which follows the multiple tube (most probable number) method, and replaced it with ISO 9308-2:2012 using the Colilert-18/Quanti-Tray method.

This change is the result of a standard revision process that has taken place over the past three years. The ISO revision process is led by an international committee comprised of scientific, industrial and business sector experts who regularly review current ISO methods and make recommendations for updates and improvements.

"ISO is considered the gold standard for quality around the world, ensuring that products, services and processes are safe and reliable," says Manja Blazer, PhD, Senior Government Affairs Manager, IDEXX Water. "With its publication as an ISO standard, the Colilert-18/Quanti-Tray method achieves additional global recognition for easy, rapid and accurate detection of coliforms and E. coli in water."

ISO 9308-2:2012, based on Colilert-18/Quanti-Tray, is the first ISO standard to use the new ISO definition of coliforms/E. coli (expression of β-galactosidase and β-glucuronidase). It is also the first ISO standard to have been validated using ISO/TR 13843 guidance on validation of microbiological methods.

IDEXX Colilert-18/Quanti-Tray has been extensively validated to detect total coliforms and E. coli in water with quantified results in as few as 18 hours, and with no further confirmation of results required. Combining a simplified testing process with innovative IDEXX technology, the Colilert-18/Quanti-Tray method delivers accurate results that allow laboratories to make confident health and safety decisions more quickly than traditional methods.

For more information about the IDEXX Colilert-18/Quanti-Tray method, please contact your local IDEXX representative or visit our website for more information.


With the June 13, 2012, launch of IDEXX-QC in Europe, our complete line of microbiology and chemistry quality control (QC) products is now available to customers worldwide. Customers in North America can also benefit from our suite of microbiology proficiency testing (PT) services. The IDEXX-QC and PT portfolio includes:

IDEXX-QC Description Catalog Number
Coliform / E. coli UN3373-W QC-TCEC
Fecal Coliform UN3373-W QC-FC
Enterococci UN3373-W QC-ENT
Enterococci DW UN3373-W QC ENT DW
Pseudomonas UN3373-W QC-PSE
Clostridium perfringens UN3373-W QC-CPER
E. coli UN3373-W QC-ECOLI
Drinking Water Chemistry QC Catalog Number
Total / Free Chlorine W QC-DW TF CHL
Nitrate W QC-DW NIT
Orthophosphate W QC-DW OPHOS
DW Minerals Concentrate W QC-DW MIN CONC
DW Minerals W QC-DW MIN
DW Hardness Concentrate W QC-DW HARD CONC
DW Hardness W QC-DW HARD
Turbidity W QC-DW TURBID
Wastewater Chemistry QC Catalog Number
Total Free / Resdual Chlorine W QC-WW TF RES CHL
Simple Nutrients W QC-WW SN
Complex Nutrients W QC-WW CN
WW Minerals Concentrate W QC-WW MIN CONC
WW Minerals W QC-WW MIN
WW Hardness Concentrate W QC-WW HARD CONC
WW Hardness W QC-WW HARD
Simple Nutrients Concentrate W QC-WW SN CONC
Complex Nutrients Concentrate W QC-WW CN CONC
Residues Concentrate W QC-WW RES CONC
Residues W QC-WW RES
Total Residual Chlorine concentrate 0.050 mg/L W QC-CHL 0.05
Total Residual Chlorine concentrate 0.100 mg/L W QC-CHL 0.10
Total Residual Chlorine concentrate 0.500 mg/L W QC-CHL 0.50
Total Residual Chlorine concentrate 1.00 mg/L W QC-CHL 1.00
Total Residual Chlorine concentrate 1.50 mg/L W QC-CHL 1.50
Total Residual Chlorine concentrate 2.00 mg/L W QC-CHL 2.00
Proficiency Testing Catalog Number
WS Microbiological PT W PT-W SM
Standard Plate Count W PT-SPC
Quantitative Coliforms W PT-QC
Microbiological PT Enterococci W PT-ENt
WW Micro W PT-W WM
WW Enterococci W PT-W WENT

Call 1-800-321-0207 in North America, 00800-4339-9111 in Europe, or visit idexx.com/waterqc to learn more.

Colilert-18/Quanti-Tray soaking up the latest AFNOR validation
AFNOR logo

IDEXX Colilert®-18/Quanti-Tray®/2000 recently received validation from AFNOR Certification for the testing of bathing water (fresh water and sea water). The certifying body of AFNOR, the French Organization for Standardization, is governed by the European standard EN 45011. Colilert-18 is the only method worldwide validated by AFNOR Certification for both drinking water (granted in 2009) and bathing water.

AFNOR NF VALIDATION certifies the comparable analytical performance of Colilert-18 and standard methods. The NF validation was granted on the basis of an independent study involving 15 laboratories. The study concluded that the Colilert®-18/Quanti-Tray®/2000 system for quantification is statistically equivalent to the reference ISO 9308-3 method. A key difference is that with the Colilert-18 method results are confirmed in 18 hours rather than the 48 to 72 hours required for the reference method.

"Municipalities, laboratories and utilities described Colilert-18 as reliable, easy to implement, easy to read and very fast," said Philippe Rousselin, PhD, EMEA regulatory manager for IDEXX Laboratories. "In particular, the efficiency allows bathing water managers to ensure active management of their bathing areas and to act quickly in the event of contamination."

The Colilert-18/Quanti-Tray quantitative method has already been approved by more than 40 countries worldwide. Recognized as an alternative method for testing of drinking water by the European Directive 98/83/EC, it is already used by 19 European countries, including Belgium, Germany, Italy, Portugal, Spain and the United Kingdom. The Colilert-18/Quanti-Tray method is also recognized as the official method for the control of bathing water in Italy and Sweden.

Call 1-800-321-0207 in North America, 00800-4339-9111 in Europe or visit our website for more information.

Pseudalert receives two thumbs-up in New Jersey

The New Jersey (NJ) Department of Health has granted Pseudalert® a waiver approval under the Public Recreational Bathing Water rule for the compliance testing of spas and hot tubs. What's more, the NJ Department of Environmental Protection now lists Pseudalert as a Department Sanctioned Analytical Method (DSAM) for compliance testing of hot tubs and spas. Customers in New Jersey and surrounding states have been sent a letter announcing both approvals.

Pseudalert can be used for presence/absence detection or with the Quanti-Tray/Quanti-Tray 2000 system for most probable number (MPN) enumeration. Detecting P. aeruginosa in 1 cfu in either 100-mL or 250-mL samples, Pseudalert gives customers results within 24 hours for noncarbonated-water samples and within 26 hours for carbonated-water samples.

Call 1-800-321-0207 or visit our website to learn more.

German environmental agency says yes to Enterolert-DW

On April 12, 2012, Enterolert®-DW/Quanti-Tray® was approved by Umweltbundesamt (UBA) for the detection of enterococci bacteria in drinking water throughout Germany. European regulations require testing drinking water for enterococci, coliforms and E. coli, as all indicate possible water contamination that could pose a health risk to humans.

Exceeding both the speed and accuracy of conventional testing methods, the Enterolert-DW test detects and quantifies enterococci in 24 hours to give water-testing laboratories faster results for compliance testing. Enterolert-DW helps water-testing laboratories and utilities make health and safety decisions more quickly and confidently.

The conventional "Slanetz and Bartley" method (ISO 7899-2) requires a technician to filter the water through a membrane, place the membrane on an agar plate to grow the bacteria for 2 days, transfer the membrane to another agar plate for confirmation and then count bacterial colonies. With ready-to-use reagents and requiring only 1 minute of hands-on time, Enterolert-DW is easier to use than the conventional method.

What's more, Enterolert-DW and the popular IDEXX Colilert®-18/Quanti-Tray® test method for coliforms and E. coli use the same platform. That means laboratories and public utilities can use a single platform to test drinking water for all key microorganisms and get accurate, complete results in just 24 hours.

Call 1-800-321-0207 in North America, 00800-4339-9111 in Europe, or visit our website.

Reminder: Free Desktop eCalendar for 2012
eCalendar Desktop

In an effort to be “greener” as a company, we now offer an electronic desktop calendar that you can download from idexx.com/water. The calendar is updated every month with a new water-related picture.

To download the calendar to a Windows® computer:

  1. Go to the IDEXX Water calendar page.
  2. Click either the Widescreen or Standard option for the current month.
  3. Right-click the image, and select Set as background.

To download the calendar to a Macintosh® computer:

  1. Go to the IDEXX Water calendar page.
  2. Click the current month. The download begins immediately.
  3. From the Apple® menu, select Dock, and then the Desktop/Screensaver icon.
  4. Click + in the wallpaper options, and add the downloaded wallpaper image.

Tip: Bookmark the calendar page so you can update your wallpaper monthly.

Tech Tip
The Quanti-Tray® platform consists of two tray formats: the 51-well Quanti-Tray and the 97-well Quanti-Tray/2000. These trays have the versatility to be used with any IDEXX 100-mL product. Both tray formats include an overflow well at the top of the tray. The well captures excess sample/media, preventing it from spilling out of the tray and is counted as a large well for reporting purposes. The overflow well is visible in both the Quanti-Tray and Quanti-Tray/2000 MPN tables.
H2O Fact
IDEXX water products have more than 110 product approvals around the world!

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