Millipore® Oasis Microbial Filtration System

Overview

The Millipore® Oasis Microbial Filtration System is an engineered solution for standardized, low-risk microbial limit testing (MLT) in pharmaceutical, biotechnology, and contract manufacturing laboratory environments. It operates on the principle of membrane filtration—drawing liquid samples under controlled vacuum across sterile, low-protein-binding membranes (e.g., mixed cellulose ester or polyethersulfone), followed by incubation and colony enumeration. Unlike traditional gravity or manual vacuum systems, the Oasis integrates mechanical stability, ergonomic design, and fluidic isolation to minimize operator variability and eliminate cross-contamination pathways. Its compact footprint and low-height base (90 mm) enable seamless integration into Class II biosafety cabinets or laminar flow hoods without compromising workspace clearance or airflow integrity. The system is not a standalone identification platform; it is a sample preparation and filtration module optimized for subsequent culture-based enumeration or rapid microbiological methods (RMM) integration.

Key Features

• Ergonomic & Space-Efficient Architecture: At just 90 mm tall and weighing 3.4 kg (including filter head), the Oasis occupies minimal bench space while enabling comfortable seated or standing operation—critical for high-throughput QC labs performing repetitive MLT workflows.
• Backflow Prevention Engineering: A field-replaceable, sterilizable check valve is housed directly within the filter head assembly, physically isolating the membrane from downstream fluid paths and eliminating retrograde contamination risk during vacuum cycling or pump shutdown.
• Modular Throughput Scaling: Supports connection to up to three independent vacuum sources (e.g., diaphragm or oil-free rotary vane pumps), enabling simultaneous operation of six filtration units—ideal for batch testing of multiple product lots or media types under identical conditions.
• Regulatory-Ready Surface Design: All external surfaces are smooth, non-porous, and chemically resistant to common disinfectants (e.g., 70% ethanol, sporicidal agents). No crevices or threaded ports exist at the user interface—reducing bioburden retention and accelerating cleaning verification cycles.
• Filter Head Serviceability: Critical wetted components—including the valve seat, gasket, and support grid—are tool-free detachable and compatible with steam sterilization (121°C, 15 psi, 15 min) per ISO 17665-1, supporting reuse in GMP environments where membrane cost or supply chain constraints apply.

Sample Compatibility & Compliance

The Oasis system accommodates standard 47-mm diameter filtration membranes and accepts aqueous, buffered, or mildly viscous solutions typical of pharmaceutical preparations (e.g., injectables, ophthalmics, oral liquids, and non-sterile APIs). It is validated for use with USP and test methods, including total aerobic microbial count (TAMC) and total combined yeasts and molds count (TYMC). Its construction materials (316L stainless steel filter head body, PTFE-sealed valves, and medical-grade elastomers) comply with USP extractables profiling requirements. When paired with a validated electronic logbook and audit-trail-enabled software (e.g., MilliporeSigma’s LabSolutions™ or third-party LIMS), the Oasis supports 21 CFR Part 11 compliance through user authentication, electronic signatures, and immutable session records.

Software & Data Management

While the Oasis itself is hardware-only and does not include embedded firmware or touchscreen controls, its operational parameters—pump runtime, channel activation sequence, and maintenance logs—are fully trackable when interfaced with compliant laboratory informatics systems. Integration with MES or QMS platforms enables automated capture of filtration start/stop timestamps, operator IDs, membrane lot numbers, and environmental monitoring data (e.g., biosafety cabinet airflow velocity) into structured audit trails. This architecture aligns with ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available) required for regulatory inspections under FDA, EMA, and PMDA frameworks.

Applications

• Routine microbial limit testing of non-sterile drug products per ICH Q5C and Ph. Eur. 5.1.2
• Environmental monitoring sample processing (e.g., water for injection, purified water, cleanroom rinse fluids)
• Raw material and excipient bioburden assessment prior to formulation
• Validation of depyrogenation and sterilization processes via challenge studies
• Supporting rapid microbiological method transfers by providing consistent, low-variability filtration substrates for ATP-bioluminescence or PCR-based detection

FAQ

Is the Oasis system suitable for sterility testing?
No—the Oasis is designed exclusively for microbial limit testing per USP /. Sterility testing requires different filtration hardware (e.g., dual-manifold, larger-diameter membranes) and stricter aseptic validation per USP .

Can the filter head be autoclaved?
Yes—the stainless steel filter head assembly (excluding vacuum tubing and electrical components) is fully autoclavable at 121°C for 15 minutes. Validation of cycle efficacy must be performed per ISO 17665-1 in each user facility.

Does the system include a built-in vacuum pump?
No—the Oasis is a pump-agnostic platform. Users must supply compatible external vacuum sources meeting minimum −80 kPa suction and flow stability specifications.

What regulatory documentation is provided with the system?
MilliporeSigma supplies a Device Master Record (DMR)-aligned User Requirements Specification (URS), Factory Acceptance Test (FAT) report, Installation Qualification (IQ) protocol templates, and Material Certificates of Conformance (CoC) for all wetted parts.