ROCKER MF5a Magnetic Filter Holder

Overview

The ROCKER MF5a Magnetic Filter Holder is an engineered solution for rapid, secure, and contamination-controlled vacuum filtration in life science laboratories. Designed around a dual-layer neodymium magnet architecture, the MF5a achieves reliable, repeatable membrane retention without threaded components or clamping mechanisms—eliminating cross-threading risks and reducing assembly time. Its operational principle relies on magnetic attraction between opposing high-strength rare-earth magnets embedded in the upper funnel body and lower base, generating uniform compressive force across the entire 47 mm filter membrane surface. This ensures consistent seal integrity under vacuum pressures up to –85 kPa, preventing bypass leakage and enabling reproducible filtration performance across users and shifts. The device is optimized for sterile applications including cell culture supernatant clarification, buffer preparation, reagent sterilization, and microbiological sample concentration—where operator variability and procedural consistency directly impact downstream assay validity.

Key Features

• Dual-layer rare-earth magnet system delivering >12 N axial holding force, maintaining full seal integrity during high-flow filtration without manual tightening
• Single-handed operation enabled by ergonomic lever-free opening/closing mechanism—reducing repetitive strain and improving workflow efficiency in high-throughput labs
• Integrated alignment ring on the base platform ensures precise 47 mm membrane centering prior to magnetic engagement, minimizing misalignment-related edge leakage
• Side-mounted vacuum port with integrated PES barbed fitting allows direct connection to standard 6–8 mm ID vacuum tubing—compatible with benchtop vacuum pumps, waste bottles, serum bottles, and borosilicate glass receivers without adapters
• Entire wetted path constructed from medical-grade polyethersulfone (PES), certified USP Class VI and ISO 10993-5 compliant; withstands repeated autoclaving at 121°C for 20 minutes without dimensional drift or hydrophobicity loss
• Chemical resistance profile includes compatibility with 70% ethanol, isopropanol, acetone, chloroform, and 1 M NaOH—enabling rigorous cleaning protocols between batches

Sample Compatibility & Compliance

The MF5a supports all standard 47 mm diameter membranes—including mixed cellulose ester (MCE), polyvinylidene fluoride (PVDF), nylon, polycarbonate track-etch (PCTE), and PES—across pore sizes from 0.1 µm to 5.0 µm. Its low-binding PES surface minimizes protein adsorption, preserving analyte recovery in low-concentration biological samples. The silicone rubber sealing gasket conforms to FDA 21 CFR 177.2350 for repeated contact with aqueous and mild organic solutions. Device construction adheres to ISO 9001-certified manufacturing processes, and material traceability documentation (including RoHS and REACH declarations) is available upon request. All units undergo 100% functional leak testing at –85 kPa prior to packaging.

Software & Data Management

As a manually operated, non-electronic filtration device, the MF5a requires no firmware, drivers, or software integration. Its design aligns with GLP/GMP documentation requirements through inherent traceability: each unit carries a laser-etched serial number and batch code for calibration log linkage and audit trail maintenance. When used in regulated environments (e.g., QC labs supporting ISO/IEC 17025 or FDA 21 CFR Part 11 workflows), the MF5a integrates seamlessly into existing electronic lab notebook (ELN) systems via standardized SOP templates that record lot numbers of associated membranes, vacuum pressure settings, filtration duration, and operator ID.

Applications

• Sterile filtration of cell culture media, supplements, and buffers prior to use in mammalian or insect cell bioreactors
• Clarification of fermentation broths and lysates in upstream bioprocessing development
• Pre-filtration of environmental water samples before microbial enumeration (e.g., membrane filtration method per EPA Method 1603)
• Removal of particulates from HPLC mobile phase solvents and standards preparation
• Routine sterilization of diagnostic reagents in clinical microbiology and molecular diagnostics labs
• Concentration of viral vectors or exosomes using low-protein-binding PVDF or PES membranes

FAQ

Can the MF5a be used with aggressive solvents such as DMSO or THF?
PES exhibits limited compatibility with DMSO and THF; prolonged exposure may cause swelling. For such solvents, we recommend verifying membrane and gasket compatibility separately and limiting contact time to <5 minutes.
Is the silicone gasket replaceable?
Yes—ROCKER supplies replacement gaskets (Part No. GSK-MF5) designed for 500-cycle durability under autoclave conditions.
Does the side-port vacuum connection affect filtration rate compared to bottom-port designs?
No measurable difference in flow rate was observed in comparative testing (n=12) against conventional bottom-port holders under identical vacuum pressure and membrane conditions.
What is the maximum recommended vacuum pressure?
Operational limit is –85 kPa (–638 mmHg); exceeding this may compromise seal integrity or cause membrane collapse with submicron pore sizes.
How often should the magnetic assembly be cleaned?
Wipe external magnet surfaces with 70% ethanol after each use; avoid abrasive cleaners or ultrasonic cleaning which may demagnetize the neodymium cores.