Rocker VF5 Glass Filtration Assembly

Overview

The Rocker VF5 Glass Filtration Assembly is a precision-engineered vacuum filtration system designed specifically for low-volume, high-sensitivity biological sample processing. Built upon classical dead-end filtration principles, the VF5 employs a borosilicate glass funnel assembly with a ground-glass membrane support surface to ensure uniform flow distribution and minimal sample retention—critical for preserving nucleic acid integrity during downstream applications such as hybridization, library preparation, and contaminant analysis. Its compact 15 mL funnel capacity and 125 mL collection bottle provide optimal headspace control and reduce evaporation risk during vacuum-assisted filtration of precious samples. The system operates under standard laboratory vacuum sources (typically –0.8 to –0.95 bar), delivering consistent flow kinetics without compromising membrane integrity or introducing leachables—ensuring compatibility with sensitive molecular assays.

Key Features

• Borosilicate glass construction throughout funnel body, base, and collection bottle—resistant to thermal shock, autoclaving (up to 121°C, 20 min), and chemical exposure from common solvents and aqueous buffers.
• Ground-glass membrane support platform ensures flat, stable positioning of 25 mm diameter membranes—minimizing channeling and maximizing effective filtration area (2.2 cm²).
• Integrated No. 5 silicone stopper provides secure, leak-free sealing between funnel and collection bottle while maintaining flexibility for repeated use and easy disassembly.
• Optimized hose interface with 8 mm (5/16 in.) internal diameter compatibility—designed for standard vacuum tubing used in benchtop vacuum manifolds and diaphragm pumps.
• Low dead-volume geometry: funnel taper and narrow neck design limit residual sample hold-up to <10 µL after filtration—essential for recovery-critical workflows including RNA purification and viral particle concentration.

Sample Compatibility & Compliance

The VF5 assembly supports all standard 25 mm membrane types—including mixed cellulose ester (MCE), polyethersulfone (PES), nylon, PVDF, and track-etched polycarbonate—enabling selection based on pore size (0.1–5.0 µm), protein binding affinity, and solvent compatibility. It is routinely employed in protocols compliant with ISO 8573-7 (airborne particulate testing), ASTM D2974 (moisture content in biomass), and USP (particulate matter in injections) when coupled with appropriate analytical validation. While not an automated instrument, its material composition and dimensional consistency support GLP-aligned documentation practices; all components are traceable via Rocker’s part numbering system (e.g., 167200-05 for full assembly) and meet RoHS Directive 2011/65/EU requirements for restricted substances.

Software & Data Management

As a manually operated, non-electronic filtration device, the VF5 requires no embedded firmware, drivers, or software integration. However, its standardized dimensions and reproducible performance make it fully compatible with digital lab notebook systems (e.g., LabArchives, Benchling) and LIMS platforms for protocol capture, batch logging, and audit trail generation. Users may assign unique identifiers to each assembly for inventory tracking and calibration history maintenance. Though lacking electronic data output, the VF5’s mechanical reliability and dimensional repeatability contribute directly to measurement traceability in validated workflows—particularly where filtration step timing, vacuum pressure, and membrane lot numbers are recorded per FDA 21 CFR Part 11–aligned SOPs.

Applications

• Nucleic acid purification: Removal of enzymatic reaction residuals post-PCR, RT-qPCR, or ligation prior to sequencing or hybridization.
• Molecular contaminant analysis: Filtration of low-volume clinical or environmental samples (e.g., cerebrospinal fluid, filtered seawater) for subsequent detection of microplastics, exosomes, or microbial aggregates.
• Cell lysate clarification: Pre-centrifugation clearing of viscous lysates in CRISPR editing workflows where protease inhibitors must remain active.
• Small-molecule drug formulation screening: Sterile filtration of nanosuspensions (<100 nm) using 0.22 µm PES membranes under controlled vacuum to assess filter clogging and throughput decay.
• Quality control in biomanufacturing: Final sterile filtration verification of buffer solutions in pilot-scale upstream processing suites.

FAQ

Can the VF5 filtration assembly be autoclaved?
Yes—the entire glass assembly (funnel, base, and 125 mL bottle) and No. 5 silicone stopper are autoclavable at 121°C for 20 minutes. Ensure complete drying before reuse to prevent condensation-related contamination.
Is the ground-glass membrane support interchangeable with other Rocker funnel models?
No—the VF5’s ground-glass support is dimensionally specific to its 15 mL funnel geometry and is not compatible with larger-capacity Rocker funnels (e.g., VF30 or VF50 series).
What vacuum pressure range is recommended for optimal performance?
A regulated vacuum of –0.85 to –0.92 bar is ideal; higher pressures may cause membrane collapse with low-pore-size filters, while lower pressures prolong filtration time unnecessarily.
How should I validate membrane integrity after filtration?
Perform a post-filtration bubble point test using isopropanol or water, following ASTM F316-11 guidelines—this is especially critical when processing sterility-sensitive samples.
Are replacement parts available separately?
Yes—individual components are stocked under Rocker part numbers: 167120-32 (15 mL funnel), 167110-18 (No. 5 silicone stopper), and 167250-05 (125 mL bottle); full assembly is 167200-05.