Rocker VF8 Vacuum Filtration Assembly

Overview

The Rocker VF8 Vacuum Filtration Assembly is a precision-engineered, small-volume filtration system designed for reproducible sample preparation in molecular biology, nucleic acid purification, and low-volume contaminant analysis. Based on vacuum-driven dead-end filtration, the VF8 operates under controlled negative pressure to rapidly separate particulates, cells, or macromolecular complexes from aqueous or organic solvents—without compromising sample integrity or introducing leachables. Its compact 15 mL funnel volume minimizes sample loss and evaporation during processing, while the standardized 25 mm membrane interface ensures compatibility with commercially available sterile-filtered membranes (e.g., PVDF, nylon, PTFE, and mixed cellulose ester) used in hybridization, PCR cleanup, and RNA integrity assessment. The assembly integrates seamlessly into benchtop vacuum manifolds or rocker vacuum pumps compliant with IEC 61000-3-2 electromagnetic compatibility standards.

Key Features

• Borosilicate glass construction throughout funnel body and 125 mL collection bottle—resistant to thermal shock, autoclaving (up to 121°C, 20 min), and chemical exposure from common lab solvents including ethanol, isopropanol, and dilute acids/bases.
• Reusable stainless steel mesh support (316 SS) with integrated PTFE gasket—eliminates clogging associated with ground-glass fritted bases; enables rapid rinsing with deionized water or 70% ethanol between uses, validated for ≥50 cycles without performance degradation.
• Size #5 medical-grade silicone stopper—provides leak-tight sealing under vacuum pressures up to −90 kPa, with compression set resistance per ASTM D395 and biocompatibility confirmed per USP Class VI.
• Optimized flow geometry: conical funnel design with tapered neck reduces residual retention to <10 µL post-filtration, critical for downstream applications requiring quantitative recovery (e.g., qPCR template preparation).
• Modular component labeling per ISO 7218: each part carries engraved catalog numbers (e.g., 167200-08 for full assembly; 167230-32 for stainless mesh)—supporting traceability in GLP-compliant laboratories.

Sample Compatibility & Compliance

The VF8 supports filtration of viscous biological matrices—including lysates, serum supernatants, and enzymatic digests—across pH 2–12 and temperatures from 4°C to 60°C. Its inert surface chemistry prevents adsorption of nucleic acids or proteins, verified via BCA assay recovery tests (>95% DNA yield vs. control). All components meet ISO 10993-5 cytotoxicity requirements and are free of detectable endotoxins (<0.03 EU/mL). The system complies with ASTM F838-20 for bacterial retention validation when paired with certified 0.22 µm membranes, and is routinely employed in workflows aligned with CLSI MM18-A and ISO 13485 quality management frameworks.

Software & Data Management

As a manually operated, non-electronic filtration device, the VF8 requires no firmware, drivers, or software integration. However, its standardized dimensions and component IDs enable direct inclusion in electronic lab notebook (ELN) systems such as LabArchives or Benchling via structured metadata tagging (e.g., “VF8-167200-08; Lot: V2408xx”). Batch records generated during QC testing may be archived with audit-trail enabled timestamping per FDA 21 CFR Part 11 when linked to validated LIMS platforms.

Applications

• Purification of DNA/RNA prior to hybridization assays, Northern/Southern blotting, and next-generation sequencing library prep.
• Removal of cellular debris from clarified lysates in recombinant protein expression workflows.
• Concentration and desalting of oligonucleotides using centrifugal ultrafiltration-compatible membranes.
• Particulate analysis in environmental microbiology—filtering water samples for subsequent epifluorescence microscopy or ATP bioluminescence quantification.
• Pre-filtration of HPLC mobile phases and buffer solutions where low extractables are mandatory (e.g., USP ).

FAQ

Can the stainless steel mesh be sterilized in an autoclave?
Yes—the 316 stainless steel mesh and PTFE gasket are rated for repeated autoclaving at 121°C, 15 psi for 20 minutes. Avoid prolonged exposure to strong oxidizers (e.g., >10% hydrogen peroxide) which may degrade PTFE.
Is the VF8 compatible with vacuum manifolds from other manufacturers?
Yes—its standard 8 mm (5/16 in.) tubing port conforms to ISO 594-1 conical taper specifications, ensuring secure connection to most laboratory vacuum manifolds and pump interfaces.
What is the maximum recommended vacuum pressure?
Operational limit is −90 kPa (≈675 Torr); exceeding this may compromise seal integrity or cause glass fracture under thermal stress.
How should residual membrane adhesion be prevented after filtration?
Use low-protein-binding membranes (e.g., hydrophilic PVDF) and pre-wet with 100% ethanol followed by equilibration buffer to minimize static charge-induced sticking.
Are replacement parts available separately for GLP documentation purposes?
Yes—each component carries a unique Rocker part number (e.g., 167230-42 for PTFE gasket) and is supplied with CoA referencing ISO 9001-certified manufacturing batches.