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E. coli in Water PT- Quantitative WP

Proficiency Testing Material


Quality Level


set of 2 ea




food and beverages

shipped in

wet ice

storage temp.



Escherichia coli

General description

E. coli in Water PT - Quantitative WP is produced in accordance with ISO/IEC 17043:2010. This sample is manufactured according to TNI requirements. However, please note, this sample may include non-TNI analytes as well. The PT portfolio allows our test components to offer significant performance data to monitor and prove competency to customers, accreditation bodies or both.

Supelco® is a global proficiency testing (PT) provider that manufactures best-in-class environmental and pharmaceutical PT products. Most water PT samples are available as concentrates or ready-to-use volumes giving the end-user flexibility in selecting samples that will fit their exact needs. Our WP program is designed to meet the quality assurance requirements in compliance with Discharge Monitoring Report - Quality Assurance Program (DMR-QA), thereby ensuring the analytical competence of your laboratory.

Type of PT Scheme: Water analysis - Water Pollution (WP)

Matrix: Water Pollution/Wastewater

Analyte/s: Values of analytes vary lot to lot.

All information regarding the use of E. coli in Water PT- Quantitative WP proficiency testing standard for E. coli testing in water can be found in the reporting packet which will be available to download at PT Portal.


E. coli in Water PT - Quantitative WP proficiency testing material is designed for the quantitative determination of E. coli in wastewater samples.

Have any questions? Explore our FAQs.
For more information on this product, please contact our PT Service Team.

Features and Benefits

We have a vast portfolio of environmental PT schemes with "fit-for-purpose" samples to help you meet the needs of the laboratory.

Our proficiency testing (PT) program is a benchmark to:

  • provide staff with an insight into their laboratory′s performance, to verify the accuracy and reliability of their testing process
  • provide a comparison of performance with that of other laboratories, nationally and internationally
  • test and educate staff, provide a better understanding of the impact of incorrect results and identify areas where there may be problems
  • provide an independent evaluation of laboratory performance
  • demonstrate to clients, colleagues and accreditation bodies that there is a commitment to quality


Set contains 2 sterile screw cap vials each containing a Vitroid (a small disk containing the possible organisms) and 2 - 99mL bottles of phosphate buffer.
(Please note, buffer solution may not be provided with your sample. If this causes any concern, please contact PT Service

Preparation Note


  • This PT sample is designed for the quantitative analysis of total and/or fecal coliform and E. coli.
  • The PT sample is provided in duplicate as a stable dehydrated Vitroid requiring hydration. An additional sample is provided for mishaps in the lab. TNI prohibits the practice of multiple tests on a PT sample unless it is normal laboratory practice and multiple analysis is conducted on a normal day to day samples.
  • A 100 mL of sterile hydration fluid is supplied with the PT sample. This is a phosphate buffer. If you are following IDEXX methods for Quanti-Tray® do not use the buffer provided and follow the directions provided with the media (suggests using Type 1 DI water.) (Please note, buffer solution may not be provided with your sample. If this causes any concern, please contact PT Service
  • When prepared according to instructions, the concentration range of the sample will be between 20 - 2400 CFU/100 mL as per TNI Fields of Testing, January 4, 2010.
  • The dehydrated Vitroid sample is stable for a time exceeding the study schedule.

General Information

  • Due to the sensitivity of microorganisms and short holding times after hydration, please read the entire instructions prior to preparation.
  • This sample is a single Vitroid and the possible concentration range is quite broad, it may be necessary to analyze the sample in a dilution series using general phosphate buffer solution.
  • This sample may be analyzed by any method appropriate for coliforms.

Sample Preparation

  • Allow the capped sample vial to equilibrate to room temperature.
  • While the sample is equilibrating to room temperature, warm the hydrating fluid in your incubator to 35 - 37 °C. This will take about 60 min. This step is not necessary but will aid the dissolution of the Vitroid. If you do not have the capability to warm the hydration fluid, allow it to reach room temperature prior to starting the next step. The hydration fluid is sterile and may be stored at room temperature up to the expiration date listed on the bottom, refrigeration is not necessary for the hydration fluid.
  • Open the sample vial and aseptically transfer the Vitroid to the hydrating fluid.
  • NOTE: The Vitroid is the colored disk within the cryotube. It will either be on top of cotton with opaque desiccant beads below the cotton or free moving in a cryotube that contains a desiccant tablet within the cap. The opaque desiccant beads and desiccant tablet are to keep the container dry and are not biologicals.
  • Allow the Vitroid to dissolve completely this may take up to 15 min. Mix by inverting gently several times, shaking may cause the cap to leak.
  • This represents the sample for analysis. Incubate at the temperature required by your method. Temperature requirements are rigorous, higher temperatures will kill the organisms and lower temperatures may suppress growth.
  • The minimum incubation time is 24 hours (or 18 hours dependent on method and media.) Further incubation time may be necessary depending on the method and media. Further dilutions are recommended to achieve a proper count, but base all counts on the whole volume sample. If you have questions please contact

Storage and Stability

Please refer to sample label for expiration date, specific storage temperature, and specific storage conditions.

Other Notes

Are you new to Supelco® Proficiency Testing? Be sure to register your account details in the PT Portal before placing your order.
This will provide access to data entry, reporting packets and final reports. Registrations will be approved shortly after your order is placed. For further questions, write to us at

When placing your order online, please indicate your study preference under the ′your reference′ column. Available studies can be viewed at the bottom of the page.
Click here to learn more about Quick-Turn Studies (on-demand proficiency tests that are offered depending on lot availability). The Quick-Turn results are released within 48-72 hours whereas scheduled study reports are released within 21 days.

Proficiency testing samples are presented as single blind. No values for the samples are released until the testing period concludes.

This PT sample is designed for the quantitative analysis of total and/or fecal coliform and E. coli. The PT sample is provided in duplicate as a stable dehydrated vitroid requiring hydration. The additional sample is provided for mishaps in the lab. Store the PT sample as directed. The dehydrated vitroid™ sample is stable for a time exceeding the study schedule.

Proficiency Testing Schedule (2021-2022)

WP21-1January 13 - February 26, 2021
WP21-2March 24 - May 7, 2021
WP21-3July 7 - August 20, 2021
WP21-4September 22 - November 5, 2021

WP22-1January 12 - February 25, 2022
WP22-2March 23 - May 6, 2022
WP22-3July 6 - August 19, 2022
WP22-4September 21 - November 4, 2022

DMR-QA (US customers only)
DMR-QA 41 March 19 - July 5, 2021

DMR-QA 42 2022 Dates TBD

Legal Information

Quanti-Tray is a registered trademark of IDEXX Laboratories, Inc.
Supelco is a registered trademark of Merck KGaA, Darmstadt, Germany
Vitroid is a trademark of Sigma-Aldrich Co. LLC



    Total coliforms 20.0 - 2400 CFU/100mL
    Total Coliform, MPN 20.0 - 2400 MPN/100 mL
    Escherichia coli 20.0 - 2400 CFU/100mL
    Escherichia coli, MPN 20.0 - 2400 MPN/100 mL
    Fecal coliforms 20.0 - 2400 CFU/100mL
    Fecal coliform, MPN 20.0 - 2400 MPN/100 mL

Storage Class Code

6.2 - Infectious substances



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Enter Lot Number to search for Certificate of Analysis (COA).

Certificate of Origin

Enter Lot Number to search for Certificate of Origin (COO).

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