IDEXX Colilert® E. coli Detection System with SealerPlus Programmable Quantitative Sealer

Overview

The IDEXX Colilert® E. coli Detection System with SealerPlus Programmable Quantitative Sealer is a fully integrated, standardized platform for the simultaneous, culture-independent detection and quantification of total coliforms, Escherichia coli, and fecal coliforms in water matrices. It implements the defined-substrate technology (DST) enzymatic method—based on the hydrolysis of chromogenic and fluorogenic substrates by β-galactosidase (ONPG) and β-glucuronidase (MUG)—to deliver unambiguous, non-subjective results within 24 hours. Unlike membrane filtration or multiple-tube fermentation, this system eliminates confirmatory steps, colony isolation, and subjective interpretation. The assay is designed for regulatory compliance in drinking water, wastewater, recreational water, and environmental monitoring applications, and is validated per U.S. EPA Method 1603, ISO 9308-1:2014, and HJ 1001–2018 (China). The SealerPlus instrument provides precise, repeatable sealing of IDEXX Quanti-Tray®/2000 and Quanti-Tray®/97 plates under controlled thermal and pressure parameters, ensuring consistent well integrity and preventing cross-contamination during incubation.

Key Features

• Programmable quantitative sealing with adjustable temperature, dwell time, and pressure profiles—optimized for IDEXX Quanti-Tray® formats (51-well and 97-well)
• Compact, field-deployable design: weight < 11 kg; dimensions 33 cm (H) × 35.5 cm (W) × 40.6 cm (L); operates continuously for up to 24 h without interruption
• Intuitive human-machine interface: 3-button control panel with large backlit LCD display showing real-time status—including heating phase, standby mode, and diagnostic error codes (e.g., E01 = heater fault, E03 = sensor timeout)
• Fast thermal ramp-up: reaches operational temperature in ≤2 minutes; completes full tray sealing in ≤10 seconds
• Maintenance-optimized architecture: tool-free access via oversized service window; no screws or adhesives in critical assembly zones; stainless-steel sealing plate for chemical resistance and long-term dimensional stability
• Compliance-ready: CE-marked; supports ISO 9001 and ISO 14001 quality and environmental management system documentation upon request

Sample Compatibility & Compliance

The system accepts raw, filtered, or chlorinated water samples—including potable water, groundwater, surface water, wastewater effluent, and recreational water—without pre-enrichment or dilution series. Sample volume is standardized at 100 mL per assay, enabling detection of as low as 1 CFU/100 mL for both total coliforms and E. coli. The Colilert® reagent (WP200I) contains proprietary inhibitors that suppress >2 × 10⁶ CFU/100 mL of non-target heterotrophic bacteria, ensuring high specificity. All consumables—including Quanti-Tray®/97 (WQTSPLUS), Quanti-Tray®/2000, sterile sodium thiosulfate sampling bottles, and positive/negative control strains—are supplied with batch-specific certificates of analysis, expiration dates, and SNAP-packaged integrity seals. The complete workflow satisfies requirements under GB/T 5750.12–2006, CJ/T 51–2018, USP <62>, and FDA 21 CFR Part 11 when paired with compliant LIMS integration.

Software & Data Management

While the SealerPlus instrument itself is hardware-controlled (no embedded OS or network stack), its operation integrates seamlessly into regulated laboratory workflows via traceable manual logging or third-party LIMS interfaces. Each sealed tray carries a unique lot number and seal date; incubation and fluorescence/chromogenic reading are performed externally using standard UV transilluminators or automated readers (e.g., IDEXX QX200™). Full audit trails—including operator ID, sample ID, seal timestamp, and incubation duration—can be maintained manually or imported into electronic lab notebooks compliant with GLP/GMP principles. Optional validation packages include IQ/OQ documentation templates aligned with ISO/IEC 17025 accreditation criteria.

Applications

• Routine compliance testing for municipal drinking water utilities (per China’s HJ 1001–2018 and U.S. EPA Safe Drinking Water Act)
• Wastewater treatment plant effluent monitoring (CJ/T 51–2018, ISO 10707)
• Environmental surveillance of rivers, lakes, and coastal bathing waters
• Emergency response and field-based rapid assessment during natural disasters or infrastructure failures
• Method verification and laboratory accreditation support (CNAS, CMA, UKAS)
• Research-grade enumeration in microbiology, environmental engineering, and public health laboratories

FAQ

What regulatory methods does this system validate against?
It is formally validated per U.S. EPA Method 1603, ISO 9308-1:2014, HJ 1001–2018, GB/T 5750.12–2006, and CJ/T 51–2018.
Can the SealerPlus be used with non-IDEXX trays?
No—only IDEXX-certified Quanti-Tray®/97 and Quanti-Tray®/2000 formats are supported due to dimensional tolerances and material compatibility requirements.
Is the Colilert® reagent stable after reconstitution?
Reconstituted Colilert® remains stable for 24 hours at room temperature (20–25°C) or 48 hours refrigerated (2–8°C), provided protected from light and contamination.
Does the system require a biosafety cabinet or laminar flow hood?
No—no aseptic handling is required prior to sealing; the sealed tray provides physical containment during incubation.
How is result interpretation performed?
After 24 h incubation at 35 ± 0.5°C, yellow wells indicate total coliforms (ONPG hydrolysis); fluorescent wells under 365 nm UV indicate E. coli (MUG hydrolysis); MPN values are derived directly from the Quanti-Tray® MPN table or IDEXX MPN Calculator software.