Food Safety
search
cart
facebook twitter linkedin
  • Sign In
  • Create Account
  • Sign Out
  • My Account
Food Safety
  • NEWS
    • Latest News
    • White Papers
  • PRODUCTS
  • TOPICS
    • Contamination Control
    • Food Types
    • Management
    • Process Control
    • Regulatory
    • Sanitation
    • Supply Chain
    • Testing and Analysis
  • PODCAST
  • EXCLUSIVES
    • Food Safety Five Newsreel
    • eBooks
    • FSM Distinguished Service Award
    • Interactive Product Spotlights
    • Videos
  • BUYER'S GUIDE
  • MORE
    • ENEWSLETTER >
      • Archive Issues
      • Subscribe to eNews
    • Store
    • Sponsor Insights
  • WEBINARS
  • FOOD SAFETY SUMMIT
  • EMAG
    • eMagazine
    • Archive Issues
    • Editorial Advisory Board
    • Contact
    • Advertise
  • SIGN UP!
Testing & AnalysisMicrobiological

Effortless Water Testing for Coliforms and Escherichia coli with Colilert® and Colisure®

By Weber Scientific.com
October 1, 2018

Colilert® is a one-step method for water quality and compliance testing, giving results for total coliform and Escherichia coli in 18 or 24 hours with less than 1 minute of hands-on time. Colilert has a full range of regulatory approvals and has become the perfect test for a wide variety of source water applications, including required regulatory compliance testing, bottled water testing, and for fresh-cut produce or fruit rinse water (before or after processing).

Approvals and recognitions include:

•    FDA/NCIMS/PMO for total coliform for plant and farm source waters; recognized for use by certified milk laboratories for negative and positive confirmation for total coliform testing

•    USEPA, AOAC, and IBWA approved for total coliforms and E. coli

•    Accepted by APHA Standard Methods for the Examination of Water and Wastewater for total coliforms and E. coli

Colilert is pre-measured, unit dosed, and ready to use with clear, easy-to-read colorimetric results. It detects a single viable coliform or E. coli per sample. The sample collection, incubation, and reading can all be done in the same vessel. Colilert can be used as a presence/absence test for total coliforms and to specifically identify the presence or absence of E. coli through fluorescence with definitive results in 24–28 hours. Quanti-Tray® can be used for the added benefit of quantification of results. An 18-hour version allows the user to read afternoon samples the next morning—before the next day’s samples arrive. “I’m thrilled to learn about this test!” is the most common comment from new Colilert users, reports Weber Scientific sales manager Asif Rahman.

How Colilert Works
The Colilert test uses proprietary Defined Substrate Technology (DST) to simultaneously detect total coliforms and E. coli. Two nutrient-indicators, ONPG and MUG, are the major sources of carbon in Colilert and can be metabolized by the coliform enzyme β-galactosidase and the E. coli enzyme β-glucuronidase, respectively. As coliforms grow in the Colilert test, they use β-galactosidase to metabolize ONPG and change the water color from colorless to yellow. E. coli use β-glucuronidase to metabolize MUG and create fluorescence. Since most noncoliforms do not have these enzymes, they are unable to grow and interfere. The few noncoliforms that do have these enzymes are selectively suppressed by the Colilert test’s specifically formulated matrix.

This approach is different from traditional media, which provide a nutrient-rich environment that supports the growth of both target organisms and nontargets. When nontargets grow and mimic target organisms, false positives occur. Growth of nontargets can also suppress target organisms and give false negatives in traditional media. How the Colisure Test Works

Colisure® also detects coliforms and E. coli but with the convenience of a long-read window and a definitive color change for both positive and negative results. A distinct magenta color means there’s no mistaking a positive result. Results are definitive at 24 hours with a read window that lasts up to 48 hours and can be used for presence/absence or quantification testing with Quanti-Tray. “This technology is truly the gold standard of rapid coliform in water testing,” according to Sharon Wilson, Weber Scientific’s vice president of marketing and product development. The Colisure test uses proprietary DST nutrient indicators CPRG and MUG to detect total coliforms and E. coli.

Automated Water Sample Handling for Coliform and E. coli Quantification
The Quanti-Tray Sealer PLUS is the next-generation sealer in the Quanti-Tray system. The sealer makes quantification with Quanti-Tray and Quanti-Tray/2000 possible while saving time and improving laboratory efficiency.

With Quanti-Tray, a 100-mL sample is divided into 51 wells. Then the most-probable-number approach is used to determine the number of bacteria in the original sample. Automation minimizes hands-on time and maximizes throughput (up to four samples per minute). The relatively large number of wells provides a high counting range of 1–200 (without dilutions) and very tight 95 percent confidence limits.

The Quanti-Tray/2000 is based on the same statistical model as the traditional 15-tube serial dilution. With the Quanti-Tray/2000, the sample is automatically divided into the proper portions when sealed by the Quanti-Tray Sealer PLUS. The system does not require the use of test tubes, Durham tubes, or any dilutions. By automatically distributing the sample into 97 wells of two different sizes, Quanti-Tray/2000 yields a counting range of 1–2,419 CFU/100 mL with a far better 95 percent confidence limit than a 15-tube serial dilution.

Weber Scientific is an authorized distributor of IDEXX products to the food and beverage industries in the U.S. and Canada.


Author(s): Weber Scientific

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Weber Scientific distributes laboratory supplies and equipment throughout North America and is focused on the specialized testing needs of the dairy and food industries.

Recommended Content

JOIN TODAY
to unlock your recommendations.

Already have an account? Sign In

  • people holding baby chicks

    Serovar Differences Matter: Utility of Deep Serotyping in Broiler Production and Processing

    This article discusses the significance of Salmonella in...
    Meat/Poultry
    By: Nikki Shariat Ph.D.
  • woman washing hands

    Building a Culture of Hygiene in the Food Processing Plant

    Everyone entering a food processing facility needs to...
    Food Prep/Handling
    By: Richard F. Stier, M.S.
  • graphical representation of earth over dirt

    Climate Change and Emerging Risks to Food Safety: Building Climate Resilience

    This article examines the multifaceted threats to food...
    Risk Assessment
    By: Maria Cristina Tirado Ph.D., D.V.M. and Shamini Albert Raj M.A.
Manage My Account
  • eMagazine Subscription
  • Subscribe to eNewsletter
  • Manage My Preferences
  • Website Registration
  • Subscription Customer Service

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the Food Safety Magazine audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of Food Safety Magazine or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • Two men standing in a produce storage facility having a discussion.
    Sponsored byOrkin Commercial

    Staying Compliant With FSMA

  • Deli Salads
    Sponsored byCorbion

    How Food Safety is Becoming the Ultimate Differentiator in Refrigerated and Prepared Foods

Popular Stories

Corporate manager talking with factory employees

Turning Resistance into Opportunity: Motivating Change in the Food Industry

Image of baby being fed infant formula

HHS Budget Request Beats Familiar Drum

Two men standing in a produce storage facility having a discussion.

Staying Compliant With FSMA

Events

June 26, 2025

How to Design and Conduct Challenge Studies for Safer Products and Longer Shelf Life

Live: June 26, 2025 at 2:00 pm EDT: During this webinar, attendees will learn how to conduct challenge studies for microbial spoilage and pathogen growth, including the common challenges encountered, laboratory selection, and use of predictive models.

July 15, 2025

Hygienic Design Risk Management: Industry Challenges and EHEDG Guidance

Live: July 15, 2025 at 11:00 am EDT: From this webinar, attendees will learn the importance of hygienic design to ensure food safety and sanitation effectiveness.

May 11, 2026

The Food Safety Summit

Stay informed on the latest food safety trends, innovations, emerging challenges, and expert analysis. Leave the Summit with actionable insights ready to drive measurable improvements in your organization. Do not miss this opportunity to learn from experts about contamination control, food safety culture, regulations, sanitation, supply chain traceability, and so much more.

View All

Products

Global Food Safety Microbial Interventions and Molecular Advancements

Global Food Safety Microbial Interventions and Molecular Advancements

See More Products
Environmental Monitoring Excellence eBook

Related Articles

  • Health Canada Extends DuPont™ BAX® System Certification to Include Composited Samples for E. coli O157:H7 Testing

    See More
  • Testing for non-O157 STEC Escherichia coli in Beef

    See More
  • Madison Chemical Co. Proclean Degreaser

    Madison Chemical’s Water-Based ProClean® DEGREASER Ideal for Food, Beverage Plants

    See More

Related Products

See More Products
  • 1118396308.jpg

    High Throughput Analysis for Food Safety

  • 0813808774.jpg

    Improving Import Food Safety

  • food safety.jpg

    Food Safety Contaminants and Risk Assessment

See More Products

Related Directories

  • MilliporeSigma

    MilliporeSigma, the U.S. life science business of Merck KGaA, Darmstadt, Germany, partners with food safety teams to enable you to improve lab testing efficiencies with reliable products and services that meet ever changing regulations. It is through our collaborations that we can advance the safety and analysis of foods and beverages using trusted brands like Millipore® with microbiology solutions for hygiene, environmental monitoring & pathogen detection, Supelco® analytical solutions for analysis of food contamination and authenticity,
  • Serim Research Corp.

    Serim® Research is a leading manufacturer of specialized test strips for multiple industries including food safety and healthcare. Our tests for measuring chlorine and QAC sanitizing solutions are preferred by many customers including national restaurants, food production and processing companies. We also manufacture tests for residual glucose, water quality
  • Anatek Labs Inc.

    Anatek Labs, Inc is a full service environmental testing laboratory, with locations in Moscow, ID and Spokane, Yakima and Wenatchee, WA. Some of our testing includes: pesticides, food pathogens, wastewater/soils, microbiology, compost, hazardous waste, PFC-PFAS, drinking water and more. Please visit our website for all tests and pricing.
×

Never miss the latest news and trends driving the food safety industry

eNewsletter | Website | eMagazine

JOIN TODAY!
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
  • SIGN UP TODAY
    • Create Account
    • eMagazine
    • eNewsletter
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • Instagram
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing