Interscience BagMixer® 400 P Laboratory Stomacher Homogenizer

Overview

The Interscience BagMixer® 400 P is a precision-engineered laboratory stomacher homogenizer designed for rapid, reproducible, and contamination-free sample preparation in microbiological, food safety, pharmaceutical, and environmental testing laboratories. Operating on the principle of controlled mechanical percussion—where a sterile, single-use sample bag is subjected to rhythmic, high-frequency horizontal beating against fixed stainless-steel plates—the BagMixer® 400 P achieves efficient cell lysis, microbial dispersion, and particle suspension without blade contact or heat generation. This non-invasive, bag-based homogenization method eliminates carryover risk between samples and ensures full compliance with ISO 6887-1, ISO 7218, and FDA Bacteriological Analytical Manual (BAM) protocols for quantitative microbial recovery. Its fixed 8 Hz (480 rpm) oscillation frequency delivers consistent shear energy input across the entire 50–400 mL working volume range, enabling reliable enumeration of aerobic mesophiles, coliforms, Listeria, Salmonella, and other target microorganisms from solid, semi-solid, or viscous matrices.

Key Features

• Q-tight® sealing system: Patented dual-lip silicone gasket design rated to withstand up to 250 kg of internal pressure, preventing leakage during vigorous homogenization—even with high-viscosity or gas-producing samples.
• 270° upward-hinged door: Enables unobstructed access to the homogenization chamber for rapid cleaning, visual inspection, and effortless bag insertion/removal—critical for high-throughput labs adhering to GLP/GMP hygiene standards.
• Full AISI 304 stainless-steel construction: Corrosion-resistant chassis, chamber walls, and door assembly ensure long-term durability, compatibility with disinfectants (e.g., 70% ethanol, 1000 ppm chlorine), and seamless integration into regulated cleanroom environments.
• Precision-timed operation: Seven preset durations (30–210 s) plus continuous (∞) mode allow method-specific optimization—supporting standardized methods requiring exact exposure times (e.g., ISO 6887-1 Annex A for food samples).
• Ergonomic design: Compact footprint (26 × 39 × 29 cm), balanced weight distribution (16.5 kg), and lightweight door (1050 g) reduce operator fatigue during repetitive daily use.
• Integrated safety drip tray (optional): Captures incidental condensate or minor seal seepage, maintaining benchtop integrity and supporting ISO/IEC 17025 audit readiness.

Sample Compatibility & Compliance

The BagMixer® 400 P accepts all internationally standardized stomacher bags (ISO 7218-compliant dimensions: 115 × 175 mm), including those from Interscience, Seward, Thermo Fisher, and other major suppliers. It accommodates heterogeneous matrices such as raw meat, dairy products, leafy greens, soil suspensions, clinical swab eluates, and powdered pharmaceutical intermediates. The absence of internal moving parts contacting the sample guarantees zero cross-contamination—making it suitable for accredited testing labs operating under ISO/IEC 17025, FDA 21 CFR Part 11 (when paired with compliant LIMS), and EU Regulation (EC) No 2073/2005. All electrical components meet CE, RoHS, and IEC 61010-1 safety directives.

Software & Data Management

As a standalone electromechanical instrument, the BagMixer® 400 P operates without embedded firmware or digital interfaces—ensuring operational reliability, minimal maintenance, and immunity to software obsolescence. Time settings are selected via tactile rotary dial with LED confirmation; no calibration or validation of electronic controls is required. For labs implementing electronic records, time selection logs can be manually entered into validated LIMS or ELN systems. The device supports full traceability when used within documented SOPs—including recording batch numbers of consumables (bag lot codes), operator ID, sample ID, homogenization duration, and environmental conditions per ISO/IEC 17025 clause 7.5.2.

Applications

• Microbiological enumeration (CFU/g or CFU/mL) in food, feed, and cosmetic testing per ISO 6887, AOAC 990.12, and USP <61>.
• Preparation of homogenates for PCR-based pathogen detection (e.g., Salmonella spp., E. coli O157:H7) where intact DNA/RNA yield is critical.
• Environmental monitoring of water filters, biofilm scrapings, and air sampling cassettes.
• Pharmaceutical environmental isolates recovery from cleanroom surfaces using neutralizing buffered peptone water (BPW) bags.
• Academic research requiring reproducible mechanical lysis of Gram-positive bacteria (e.g., Bacillus, Staphylococcus) without enzymatic or thermal bias.

FAQ

Is the BagMixer® 400 P compatible with ISO-certified stomacher bags from third-party manufacturers?
Yes—its chamber geometry and clamping force profile comply with ISO 7218 Annex B specifications, ensuring secure fit and uniform energy transfer across all standard 115 × 175 mm bags.
What maintenance is required to sustain performance over time?
Routine cleaning with 70% ethanol or approved hospital-grade disinfectants; annual visual inspection of Q-tight® gasket integrity and door hinge tension; damper replacement every 3 years (warranty-covered upon registration).
Can the device be validated for use in GMP-regulated environments?
Yes—its deterministic mechanical design, absence of software, and traceable time-setting mechanism support IQ/OQ documentation per ASTM E2500 and EU Annex 15 guidelines.
Does the fixed 8 Hz speed limit method flexibility?
No—it reflects an empirically optimized frequency balancing microbial release efficiency, bag integrity, and temperature stability; variable-speed stomachers introduce uncontrolled shear variance incompatible with standardized enumeration.
How does the 270° door improve cleaning validation?
It allows direct line-of-sight inspection of all chamber surfaces and eliminates shadow zones—enabling swab sampling per ISO 14644-1 and residue verification per PDA TR29.