Millipore Prostak™ UF Membrane Stack

Overview

The Millipore Prostak™ UF Membrane Stack is an engineered ultrafiltration (UF) module designed for scalable, single-use bioprocessing applications in downstream purification workflows. Built on a solvent-resistant polypropylene support structure, the stack utilizes thermal fusion bonding—rather than adhesive-based lamination—to integrate multiple layers of regenerated cellulose (RC) ultrafiltration membranes. This manufacturing process eliminates extractables and leachables associated with conventional adhesives, ensuring compatibility with stringent regulatory requirements for biopharmaceutical manufacturing, including adherence to USP Class VI biological safety standards and ISO 10993-5 cytotoxicity testing. The device operates on tangential flow filtration (TFF) principles, enabling high-recovery concentration and diafiltration of labile biomolecules—including monoclonal antibodies, recombinant proteins, viral vectors, and therapeutic peptides—without compromising structural integrity or activity.

Key Features

• Solvent-resistant construction: Regenerated cellulose membranes thermally fused to polypropylene support layers—no adhesives, no organic binders, no silicone-based sealants.
• Chemical compatibility: Stable in ≥70% ethanol, acetonitrile, tetrahydrofuran, ethyl acetate, and acetone—enabling organic-phase diafiltration and recovery of hydrophobic molecules such as insulin analogs and glycopeptides.
• Configurable architecture: Available in 4-layer, 10-layer, and 20-layer stack configurations to match process scale—from benchtop development (≤5 L feed volume) to pilot-scale processing (up to 100 L).
• Consistent pore geometry: Tight molecular weight cut-off (MWCO) distribution (e.g., 10 kDa, 30 kDa, 100 kDa options) ensures reproducible retention profiles across batches and scales.
• Single-use design: Pre-sterilized via gamma irradiation (25–35 kGy); validated for ≤72-hour operational stability under standard TFF conditions (pH 3–10, ≤40°C).

Sample Compatibility & Compliance

The Prostak™ UF Membrane Stack demonstrates broad compatibility with biologics and small-molecule APIs. It is routinely employed for endotoxin removal (LAL assay-verified reduction >3-log), buffer exchange of heat-sensitive enzymes, and concentration of low-yield extracellular vesicles. Its non-pyrogenic, low-protein-binding RC membrane surface minimizes fouling during extended operation with complex feeds such as clarified CHO cell harvests or plasma-derived fractions. Regulatory documentation includes full material traceability (ISO 9001-certified supply chain), Certificate of Conformance per ASTM F2622 (membrane integrity), and compatibility data aligned with ICH Q5A(R2) guidelines for viral clearance validation studies.

Software & Data Management

While the Prostak™ UF Membrane Stack is a passive, hardware-only component, it integrates seamlessly into automated TFF platforms—including MilliporeSigma’s Pellicon® 3 and TangenX™ Sartocon® systems—that support FDA 21 CFR Part 11-compliant electronic batch records. When used with compatible controllers (e.g., Sartorius BPS or Repligen KrosFlo® Research II), real-time monitoring of transmembrane pressure (TMP), flux decay, and permeate conductivity enables automated hold-point triggers and audit-trail generation for GLP/GMP environments. All lot-specific performance data—including pre-use integrity test results and post-use extractables profiling—are archived in MilliporeSigma’s Digital Product Passport portal.

Applications

• Concentration and diafiltration of monoclonal antibodies (mAbs) and antibody–drug conjugates (ADCs) in clinical-stage purification.
• Endotoxin removal from peptide-based therapeutics and oligonucleotide formulations prior to lyophilization.
• Organic solvent-compatible diafiltration for polysaccharide purification (e.g., hyaluronic acid, chitosan derivatives) and synthetic peptide desalting.
• Downstream processing of AAV and lentiviral vectors—leveraging low nonspecific binding and minimal shear stress during recirculation.
• Process development studies requiring rapid scalability assessment between 0.1 m² and 2.5 m² effective filtration area.

FAQ

Is the Prostak™ UF Membrane Stack suitable for use with high-concentration protein solutions (>100 g/L)?
Yes—its reinforced polypropylene housing and optimized flow channel geometry minimize concentration polarization, supporting stable operation at protein concentrations up to 150 g/L when paired with appropriate crossflow rates.
Can it be reused after cleaning-in-place (CIP) protocols?
No—it is strictly designated as a single-use device; reuse is not validated and may compromise membrane integrity, sterility assurance, or regulatory compliance.
Does MilliporeSigma provide installation qualification (IQ) and operational qualification (OQ) documentation?
Yes—upon request, customers receive a comprehensive qualification package including test protocols, acceptance criteria, and raw data templates aligned with Annex 15 and ISPE GAMP 5 guidance.
What are the recommended storage conditions?
Store unopened units at 4–25°C in original packaging; avoid exposure to UV light or ozone-generating environments to preserve membrane hydrophilicity.
How does the thermal fusion process impact membrane pore uniformity compared to solvent-cast alternatives?
Thermal fusion preserves native RC crystallinity and avoids solvent-induced phase separation artifacts, resulting in narrower MWCO distributions and higher hydraulic permeability consistency across manufacturing lots.