IDEXX Quanti-Tray 2000 97-Well MPN Quantification Tray

Overview

The IDEXX Quanti-Tray 2000 97-Well MPN Quantification Tray is a standardized, culture-based enumeration device engineered for precise, statistically robust quantification of indicator microorganisms in water matrices. It implements the Most Probable Number (MPN) statistical model—internationally recognized under ISO 9308-2:2012 and validated per GB 5750.12–2006 (Standard Methods for Examination of Drinking Water, China) and US EPA Method 1604. Unlike conventional multi-tube fermentation, the 97-well tray eliminates manual dilution series, glassware, Durham tubes, and volumetric transfers. Instead, it relies on fixed-substrate technology (DST) enzyme substrate media—specifically MMO-MUG formulations—to enable simultaneous detection and confirmation of enzymatic activity (e.g., β-D-glucuronidase for E. coli, β-D-galactosidase for total coliforms) directly within each well. Upon incubation at 35 ± 0.5 °C for 18–24 hours, fluorescent or colorimetric endpoints are scored visually or via automated readers. The resulting positive/negative well pattern is converted to an MPN value using standardized MPN lookup tables or integrated software algorithms, delivering a quantitative result with defined 95% confidence intervals.

Key Features

• High-resolution quantification range: 1–2,419 MPN/100 mL without sample dilution—ideal for high-bioburden matrices including wastewater, surface water, and groundwater.
• Statistical rigor: Based on the same probabilistic foundation as the 15-tube MPN method but with enhanced precision—narrower 95% confidence limits due to increased replicate count (97 independent wells vs. 15 tubes).
• Reduced hands-on time: Sample loading requires <15 seconds per tray when used with the IDEXX Quanti-Tray Sealer 2009D; total operator involvement is under 1 minute per assay.
• Elimination of procedural variability: No pipetting errors, no tube labeling, no gas trap assembly, and no subjective interpretation of gas production—only objective endpoint detection (fluorescence or color change).
• Full traceability: Each tray is supplied sterile, individually packaged in SNAP-sealed pouches, and accompanied by batch-specific certificates of analysis, including lot number and expiration date.
• Regulatory alignment: Designed exclusively for use with DST enzyme substrate media compliant with GB 5750.12–2006, ISO 9308-2:2012, and US EPA-approved protocols—supporting audit-ready documentation for GLP and GMP environments.

Sample Compatibility & Compliance

The Quanti-Tray 2000 is validated for use with untreated and treated water samples across diverse regulatory categories: potable water (distribution systems, finished water), recreational water (pools, spas), environmental water (rivers, lakes, aquifers), and wastewater effluents. It supports detection of five key microbial indicators: total coliforms, Escherichia coli, fecal coliforms (thermotolerant coliforms), enterococci, and Pseudomonas aeruginosa. When paired with MMO-MUG DST medium, it delivers confirmatory identification of E. coli in a single incubation step—eliminating need for secondary confirmation per ISO 9308-1:2014 or APHA Standard Methods 9222B. All trays undergo pre-shipment pressure integrity testing to prevent inter-well leakage or cross-contamination—a critical requirement for MPN validity. Manufacturing and packaging comply with ISO 13485 principles, and final product certification includes conformance to GB 5750.12–2006 Annex C and ISO 9308-2:2012 Clause 6.2.

Software & Data Management

While the 97-well tray itself is a passive consumable, its integration into regulated workflows is supported through compatibility with LIMS-ready platforms and IDEXX’s proprietary Quanti-Tray Reader software (optional). The sealed tray enables unambiguous digital recording of positive well patterns via high-resolution imaging; results can be exported in CSV or PDF format with embedded metadata (lot ID, analyst ID, incubation timestamp, instrument ID). For laboratories operating under FDA 21 CFR Part 11 requirements, the full ecosystem—including sealer log files, tray batch records, and reader audit trails—supports electronic signature implementation and secure data archiving. All DST media batches include full Certificate of Analysis with sterility test reports, endotoxin limits (<0.5 EU/mL), and performance verification against reference strains (E. coli ATCC 11775, Enterococcus faecalis ATCC 29212).

Applications

This quantification tray serves as a primary method in municipal water quality surveillance programs, environmental monitoring networks, food and beverage facility environmental monitoring (EM), healthcare facility water safety plans (WSMP), and emergency response field testing. Its broad dynamic range makes it especially suitable for compliance testing of wastewater discharge permits (e.g., NPDES), source water vulnerability assessments, and post-disinfection validation in distribution systems. In clinical and pharmaceutical settings, it supports routine monitoring of purified water (PW) and water-for-injection (WFI) systems per USP <1231> and Ph. Eur. 2.2.3. The absence of hazardous reagents, minimal waste generation (no broken glass or liquid biohazard disposal), and compatibility with portable sealers further enable deployment in mobile labs and disaster zones where infrastructure is compromised.

FAQ

Is the Quanti-Tray 2000 compatible with non-IDEXX enzyme substrate media?
No. Only DST-formulated MMO-MUG media certified for use with IDEXX Quanti-Tray systems ensure correct substrate concentration, pH buffering, and inhibition profiles required for valid MPN calculation and regulatory acceptance.
Can results be reported directly to regulatory agencies without confirmation?
Yes—when used with EPA- or ISO-validated protocols and documented chain-of-custody, the 97-well MPN result is considered definitive for E. coli and total coliforms per GB 5750.12–2006 and ISO 9308-2:2012.
What is the shelf life and storage requirement for unused trays?
Trays are stable for 12 months from manufacture when stored at 2–8 °C in original sealed packaging; avoid freezing or exposure to UV light.
Does the tray require calibration or user verification before use?
No calibration is needed. Each batch undergoes factory verification for well integrity, sterility, and dimensional accuracy per ISO 8573-1 and ASTM D6225-19 Annex A1.
How does the 97-well tray compare to the 51-well version in terms of statistical power?
The 97-well configuration provides tighter 95% confidence intervals—particularly above 200 MPN/100 mL—and extends the upper detection limit by over 12-fold, eliminating dilution steps for high-turbidity or high-coliform samples.