WS-Microbiological PT - Sample (1-10)

Proficiency Testing Material


Quality Level


set of 10 ea



Featured Industry

Food and Beverages

shipped in

wet ice

storage temp.


General description

Water Supply (WS) - Microbiological PT - Sample (1-10) is produced in accordance with ISO/IEC 17043:2010. Also referred to as Potable Water or Water Supply sample, this sample is manufactured according to TNI requirements. However, please note, this sample may include non-TNI analytes as well. The lower criteria from the TNI tables mimic the levels common to drinking water samples.

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 WS program is designed to meet the quality assurance requirements in compliance with the Safe Drinking Water Act (SDWA), thereby ensuring the analytical competence of your laboratory or drinking water facility.

Type of PT Scheme:
Water analysis - Water Supply (WS)

Matrix: Water Supply/Drinking water

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

All information regarding the use of Microbiological PT - Sample (1-10) proficiency testing standard can be found in the reporting packet which will be available to download at PT Portal.


Water Supply (WS) - Microbiological PT - Sample (1-10) is an environmental/microbiological proficiency testing material, designed for the determination of Total/Fecal Coliforms and E. coli bacteria in drinking water 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

Preparation Note


  • This sample set contains 10 vials each containing a dehydrated tablet containing possible organisms.
  • Ten sterile 100 mL phosphate buffered hydrolyzing solutions are also provided. (Please note, buffer solution may not be provided with your sample. If this causes any concern, please contact PT Service ptservice@milliporesigma.com.)Each sample vial is uniquely marked with a sample number and color coded cap (Samples 1, 6 - Clear, Sample 2, 7 - Red, Sample 3, 8 - Blue, Sample 4, 9 - Yellow, Samples 5, 10 - Green.)
  • The buffer bottles are NOT labeled. Remember to label the buffer bottles prior to mixing.
  • The vials containing the dehydrated sample must be stored at 4 °C.
  • The sample is the colored disk. If the disk is lodged in the cap, drop entire cap into the hydration fluid. Ensure the disk has dissolved completely (no color remains) and aseptically remove the cap prior to analysis.
  • The hydrolyzing fluid may be stored at room temperatures. The bacteria are provided in dehydrated form for enhanced stability. They must be re-hydrated prior to performing the tests. The vials holding the bacteria are sterile in the sealed box. Once the box is opened, it is recommended hydration and analysis is started immediately.
  • Each disk contains a high concentration of bacteria.
  • Before you begin, make certain that appropriate methods and media are being used.
  • Label each dilution bottle with the sample number, the study number prior to hydrolyzing the samples.
  • All of these numbers can be found on the vial labels. Make sure to use a permanent marker that is water insoluble.
  • Do not transfer any disks into hydrolyzing liquid prior to warming it. If you are using an enzyme substrate test, follow manufacturer′s instructions.
  • If the result is questionable at the end of the incubation period, you may incubate for an additional 4 hours or as provided in the method. It is important that you report values for both Total Coliform and Fecal/E.Coli Coliform. You must report all samples to receive an evaluation.

Preparation Instructions

  • Remove the sample vials and dilution bottles from refrigeration and allow them to equilibrate to room temperature.
  • Open the bottle and aseptically transfer a dehydrated tablet to the bottle.
  • Label the bottle, cap and shake gently. The tablet will dissolve completely in about 15 min.
  • Repeat the above procedure with each sample. Due to the sensitivity of the organisms, analysis should be completed within 1 hour of hydration. Each sample will contain a concentration of bacteria from 20 to 500 CFU/100mL.
  • You may dilute the sample with phosphate buffer to meet your method needs.

Reporting Instructions

Analyze the sample by your normal procedures and report results for each sample as present (“1”) or absent (“0”) on the enclosed report form. If you enumerate, report in the space provided for MPN or cfu/100mL.

Storage and Stability

  • Please refer to sample label for expiration date, specific storage temperature, and specific storage conditions.
  • If storage conditions are not provided on the label, it is intended for room temperature storage.

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 ptservice@milliporesigma.com.

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 product contains proficiency testing sample(s) for analysis by your laboratory. Result of these measurements are to be reported within the timeframe of a study listed below. When ordering this product, select the appropriate study option for your laboratory′s requirements.

Set contains 10 sterile screw cap vials each containing a Vitroid (a small disk containing the possible organisms) and 10 - 99 mL bottles of phosphate buffer. Each sample vial is uniquely marked with a sample number. The vials containing the dehydrated sample must be stored as directed. The dehydrated Vitroid sample is stable for a time exceeding the study schedule.

Proficiency Testing Schedule (2021-2022)

Drinking Water
WS21-1January 13 - February 26, 2021
WS21-2March 24 - May 7, 2021
WS21-3 July 7 - August 20, 2021
WS21-4 September 22 - November 5, 2021

WS22-1January 12 - February 25, 2022
WS22-2March 23 - May 6, 2022
WS22-3 July 6 - August 19, 2022
WS22-4 September 21 - November 4, 2022

Legal Information

Supelco is a registered trademark of Merck KGaA, Darmstadt, Germany
Vitroid is a trademark of Sigma-Aldrich Co. LLC



    Total coliforms 0.00 - 500 CFU/100mL
    Escherichia coli 0.00 - 500 CFU/100mL
    Fecal coliforms 0.00 - 500 CFU/100mL


6.2 - Infectious substances

WGK Germany


Flash Point F

Not applicable

Flash Point C

Not applicable

Certificate of Analysis

Certificate of Origin

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

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