INLABTEC Serial Diluter TA

Overview

The INLABTEC Serial Diluter TA is an automated, benchtop serial dilution system engineered for precision, reproducibility, and contamination control in microbiological and food safety laboratories. It operates on a fixed-volume, positive-displacement principle using calibrated glass or polymer graduated pipettes (0–10 mL), integrated with capacitive liquid-level sensing and programmable peristaltic pumping. Unlike manual or semi-automated dilution workflows—where variability arises from operator technique, vortex duration, or pipetting inconsistency—the Serial Diluter TA delivers deterministic dilution ratios with ≤0.6% volumetric error at 9 mL, enabling compliance with ISO 6887-1, ISO 7218, and FDA Bacteriological Analytical Manual (BAM) Chapter 3 requirements for sample preparation in quantitative microbial enumeration.

Key Features

• High-fidelity liquid handling: Equipped with traceable, class-A graduated pipettes (0–10 mL) meeting ISO 648 and ISO 1042 tolerances; certified accuracy of ±0.05 mL at the 1 mL mark ensures metrological integrity across dilution series.
• Autoclavable 316 stainless steel dilution bag holder: Designed for six standard ISO-compliant stomacher bags; fully compatible with steam sterilization (121 °C, 20 min), eliminating carryover risk between batches in GLP/GMP environments.
• Non-contact bag opening and filling: Integrated mechanical actuator opens sealed dilution bags without manual manipulation, minimizing operator exposure and surface contamination during high-throughput processing.
• Adaptive mixing protocol: Automatically determines optimal homogenization time based on fluid viscosity and bag geometry—or allows user-defined mixing from 0.5 to 99 seconds—ensuring uniform suspension prior to sampling without over-shearing sensitive microorganisms.
• Real-time system diagnostics: Dual-sensor monitoring detects empty diluent reservoirs and pipette tip overflow conditions, triggering simultaneous audible and visual alerts to prevent incomplete dilutions or cross-contamination events.
• Electrical safety and environmental resilience: Rated IP20 per IEC 60529; operates reliably under ambient conditions from 10–40 °C and up to 80% RH at 31 °C—validated for use in ISO Class 5–8 cleanrooms and routine QC labs.

Sample Compatibility & Compliance

The Serial Diluter TA is validated for aqueous diluents only—including phosphate-buffered saline (PBS), peptone water, and Ringer’s solution—excluding strong acids (e.g., >1 M HCl), strong bases (e.g., >0.1 M NaOH), and organic solvents (e.g., ethanol, acetone) that may compromise pipette calibration or elastomer pump tubing integrity. Its workflow aligns with ISO/IEC 17025:2017 clause 7.2.2 (method validation), supports audit-ready documentation per FDA 21 CFR Part 11 when paired with compliant LIMS integration, and meets the physical design criteria for Category 2 contamination protection (EN 61326-1) in laboratory instrumentation.

Software & Data Management

While the Serial Diluter TA operates via intuitive front-panel controls with LED status indicators and rotary encoder input, it supports optional RS-232 or USB-to-serial connectivity for integration into centralized laboratory data systems. All operational parameters—including dilution factor, mixing duration, pump speed, and error logs—are timestamped and exportable as CSV for traceability. When deployed within regulated environments (e.g., pharmaceutical microbiology or contract testing labs), the device’s deterministic behavior and lack of embedded software logic eliminate the need for formal software validation under Annex 11; however, configuration records and usage logs must be retained per ALCOA+ principles for inspection readiness.

Applications

• Standardized serial dilution for aerobic plate count (APC), coliform, and Salmonella enrichment in food, feed, and environmental swab testing.
• Preparation of inocula for antimicrobial susceptibility testing (AST) per CLSI M07 and EUCAST guidelines.
• Reproducible dilution series in water quality analysis (e.g., heterotrophic plate count per ISO 6222).
• Supporting ISO 11133-compliant culture media performance verification through controlled dilution of reference strains.
• Enabling walk-away operation during overnight or shift-based microbiological workflows without sacrificing measurement fidelity.

FAQ

Is the Serial Diluter TA compatible with non-aqueous diluents such as ethanol or glycerol solutions?
No. The system is validated exclusively for aqueous diluents. Organic solvents or highly viscous glycerol solutions may degrade pump tubing, impair sensor response, and invalidate volumetric calibration.

Can the dilution bag holder be sterilized in an autoclave without disassembly?
Yes. The entire 316 stainless steel holder—including mounting brackets and actuation arms—is rated for full-cycle autoclaving (121 °C, 103 kPa, 20 minutes) without dimensional drift or corrosion.

Does the system support variable dilution factors (e.g., 1:5, 1:25) or only fixed 1:10 increments?
It performs fixed-ratio serial dilutions (typically 1:10) using pre-calibrated pipettes. Variable ratios require manual intervention or external pipetting; the instrument does not feature programmable multi-step volume dispensing.

What maintenance intervals are recommended for long-term accuracy?
Pipettes should be recalibrated annually per ISO/IEC 17025 requirements; pump tubing requires replacement every 6 months under continuous use or after 500 cycles, whichever occurs first.

Is the device compliant with electromagnetic compatibility (EMC) standards for use in hospital or clinical lab settings?
Yes. It conforms to EN 61326-1:2013 for laboratory equipment, including immunity to electrostatic discharge (IEC 61000-4-2), radiated RF fields (IEC 61000-4-3), and electrical fast transients (IEC 61000-4-4).