Microbial Limit Tester LM-Z600 Stand-Mounted System

Overview

The LuMeley LM-Z600 Stand-Mounted Microbial Limit Tester is an engineered solution for quantitative microbial enumeration in pharmaceutical, biotechnology, and quality control laboratories. Designed in strict accordance with Chinese Pharmacopoeia (ChP) General Chapter 1105 and aligned with international standards including USP <61>, EP 2.6.12, and ISO 8573-7, the system implements vacuum-driven membrane filtration to isolate viable microorganisms from liquid samples—including injectables, ophthalmic solutions, raw materials, and purified water. Unlike benchtop vacuum manifolds requiring individual flask connections, the LM-Z600 integrates a rigid stainless steel support frame with six independently controllable filtration stations, eliminating the need for intermediate collection flasks and reducing contamination risk during fluid transfer. The system operates exclusively with the LuMeley LM-B02 diaphragm liquid pump—designed for oil-free, pulse-free aspiration with chemical resistance to common solvents and disinfectants—ensuring consistent flow rates across all channels and minimizing membrane clogging or bubble formation during filtration.

Key Features

• Six independent threaded filter head mounts enable simultaneous processing of up to six samples without cross-channel interference.
• Individual rotary toggle switches provide discrete on/off control per channel—supporting staggered sample loading, partial runs, and real-time workflow optimization.
• Modular compatibility with both reusable stainless-steel filter cups (threaded interface) and single-use sterile filter assemblies—facilitating GMP-aligned changeover between routine QC and high-containment applications.
• Pump heads feature standardized M12 thread geometry, allowing rapid flame sterilization using handheld butane torches between consecutive batches—a critical capability for labs performing sequential sterility testing under ISO 14644-1 Class 5 environments.
• Electrolytically polished 304 stainless steel chassis resists pitting, passivates naturally after cleaning, and complies with ASME BPE surface roughness requirements (Ra ≤ 0.8 µm) for pharmaceutical contact surfaces.
• Compact footprint (670 × 130 × 100 mm) optimizes laminar flow hood integration; total mass of 4.5 kg ensures stability during vacuum operation without anchoring.

Sample Compatibility & Compliance

The LM-Z600 supports filtration of aqueous, low-viscosity, and mildly surfactant-containing solutions within pH 3–10 and temperature range 5–40 °C. It accommodates standard 47 mm diameter membranes (cellulose ester, PVDF, PTFE) and integrates seamlessly with commercially available microbiological test kits—including Millipore® Steritest™, Pall® Envirochek™, and Sartorius™ Minisart™ NML. All wetted components meet USP Class VI biocompatibility criteria. The system’s mechanical design conforms to IEC 61010-1 safety standards for laboratory equipment. When operated with validated protocols and calibrated LM-B02 pump units, data generated satisfies audit requirements for FDA 21 CFR Part 11-compliant electronic records (when paired with compliant LIMS or ELN software), and supports GLP/GMP documentation traceability through manual log entry or external instrument integration.

Software & Data Management

As a semi-automatic hardware platform, the LM-Z600 does not incorporate embedded firmware or touchscreen controls. This architecture intentionally minimizes validation burden—eliminating the need for IQ/OQ/PQ of onboard software and aligning with Annex 11 principles for “simple devices.” All operational parameters (e.g., filtration time per channel, pump runtime, operator ID) are recorded externally via paper logs or integrated LIMS modules. For laboratories implementing digital workflows, the LM-Z600’s predictable mechanical behavior enables precise timing synchronization with automated colony counters (e.g., ProtoCOL 3, iQ-Scan) and facilitates structured metadata capture—including filter lot numbers, membrane pore size, incubation conditions, and CFU enumeration results—within validated electronic batch records.

Applications

• Routine microbial limit testing of non-sterile pharmaceutical products per ChP/USP/EP monographs.
• Environmental monitoring of purified water and WFI distribution systems.
• Raw material bioburden assessment prior to sterilization or formulation.
• Process validation support for filtration steps in aseptic manufacturing.
• Educational training in GMP-compliant membrane filtration techniques.
• Contract laboratory service delivery where regulatory flexibility and hardware reproducibility are prioritized over automation.

FAQ

Is the LM-Z600 compliant with USP & EP requirements for microbial limit testing?
Yes—the system implements vacuum filtration methodology specified in USP <61> and EP 2.6.12, provided users select appropriate membrane types, pore sizes (typically 0.45 µm), and validate recovery efficiency per USP <1227>.
Can the LM-Z600 be used with non-LuMeley pumps?
No—it is mechanically and pneumatically optimized for use only with the LM-B02 diaphragm liquid pump to ensure stable vacuum levels (≤ −85 kPa), flow consistency, and leak-tight coupling.
What sterilization methods are validated for reusable filter cups?
Reusable cups are autoclavable at 121 °C for 30 minutes (gravimetric cycle); dry heat (160 °C, 2 hours) and VHP treatment are also compatible based on material certification.
Does the LM-Z600 require electrical safety certification for EU markets?
Yes—units shipped to EEA countries carry CE marking under Directive 2014/35/EU (Low Voltage Directive) and 2014/30/EU (EMC Directive), with test reports available upon request.
How is calibration maintained across multiple channels?
Channel-to-channel flow uniformity is verified during factory acceptance testing using calibrated flow meters; end-users perform periodic verification using timed volumetric displacement (e.g., 100 mL water filtered per channel) per SOP.