ROCKER MF3 Magnetic Filter Holder

Overview

The ROCKER MF3 Magnetic Filter Holder is an engineered solution for rapid, sterile, and operator-friendly vacuum filtration in life science laboratories. Designed around a dual-layer neodymium magnet coupling system, the MF3 achieves secure, repeatable membrane retention without threaded or clamped mechanisms—eliminating cross-threading risk and reducing setup time by up to 60% compared to conventional filter holders. Its core principle relies on magnetic attraction between opposing high-strength magnets embedded in the funnel body and base, generating uniform compressive force across the full 47 mm membrane diameter. This ensures consistent seal integrity under vacuum pressures up to −85 kPa, minimizing bypass leakage and supporting reproducible filtration performance required for quantitative applications such as microbial enumeration, particulate analysis, and sample clarification prior to HPLC or mass spectrometry.

Key Features

• Dual-layer rare-earth magnet assembly provides >12 N axial holding force, enabling one-handed opening/closing while maintaining leak-tight sealing during active filtration.
• Precision-machined alignment ring on the base ensures centric placement of standard 47 mm membranes—reducing misalignment-related channeling and improving filtration uniformity.
• Side-mounted vacuum port with integrated PES Luer-lock fitting allows direct connection to vacuum tubing; compatible with common laboratory vacuum sources including diaphragm pumps, oil-free scroll pumps, and central vacuum systems.
• Full-body construction from medical-grade polyethersulfone (PES) offers exceptional chemical resistance to alcohols, ketones, esters, and halogenated solvents—validated per ISO 10993-5 cytotoxicity testing.
• Autoclavable at 121°C, 15 psi for 20 minutes (up to 50 cycles); silicone rubber gaskets retain elasticity and compression set <15% after repeated sterilization.
• Graduated 300 mL borosilicate-glass-equivalent PES reservoir with 50 mL刻度 increments supports volumetric monitoring without secondary measurement devices.

Sample Compatibility & Compliance

The MF3 accommodates all standard 47 mm membrane types—including mixed cellulose ester (MCE), polyvinylidene fluoride (PVDF), nylon, and track-etched polycarbonate—without adapter requirements. Its low-binding PES surface minimizes protein adsorption (<0.5 µg/cm² for BSA), making it suitable for low-concentration biomolecule recovery. The device conforms to ISO 7218:2017 (microbiology of food and animal feeding stuffs), ASTM D1193-06 (Type II water purification validation), and supports GLP-compliant documentation when used with audit-trail-enabled vacuum controllers. All materials comply with USP Class VI biological safety standards and are free of detectable endotoxins (<0.03 EU/mL per LAL assay).

Software & Data Management

While the MF3 operates as a standalone mechanical filtration platform, its design integrates seamlessly into digital lab workflows. When paired with ROCKER’s optional VACUUBRAND®-compatible vacuum controllers (e.g., RC6S with RS485 output), real-time pressure logging, cycle counting, and alarm-triggered event capture can be recorded via LabArchives ELN or Benchling. The standardized 47 mm footprint enables automated handling by liquid handlers equipped with gripper modules (e.g., Tecan Fluent, Hamilton STAR). All component materials are traceable via batch-specific CoA documentation provided upon request.

Applications

• Microbial colony enumeration (ISO 7899-2, EPA Method 1603) using membrane filtration of water, beverages, and pharmaceutical rinse solutions.
• Clarification of cell culture supernatants and fermentation broths prior to downstream chromatography or ultrafiltration.
• Particulate matter analysis in injectables and ophthalmic solutions per USP and Ph. Eur. 2.9.19.
• Pre-filtration of environmental samples (soil extracts, wastewater) before ICP-MS or AAS metal quantification.
• Sterile filtration of buffers and reagents in cGMP environments where single-use alternatives are cost-prohibitive.

FAQ

Can the MF3 be used with aggressive organic solvents such as DMF or THF?
Yes—the PES body exhibits >95% tensile strength retention after 72-hour immersion in DMF, THF, and acetonitrile at room temperature, per ASTM D543-14.
Is the silicone gasket compliant with FDA 21 CFR 177.2600 for repeated food contact?
Yes—certified food-grade silicone (Shore A 50 ± 5) meets FDA 21 CFR 177.2600 and EU Regulation (EC) No. 1935/2004 requirements.
Does the MF3 support inline pressure monitoring during filtration?
The side-port Luer fitting accepts standard 1/8″ NPT pressure transducers; ROCKER recommends the Validyne DP15 series for ±0.5% FS accuracy in vacuum range.
How many autoclave cycles are validated for the complete assembly?
Accelerated aging tests confirm structural integrity and seal performance for ≥50 cycles at 121°C/15 psi, with no observable discoloration or warping.
What is the maximum recommended vacuum level for continuous operation?
Optimized performance is maintained at −85 kPa (12.3 psi vacuum); sustained operation above −90 kPa may reduce gasket service life due to increased compression creep.