STF Tangential Flow Filtration System

Overview

The STF Tangential Flow Filtration (TFF) System is a fully domestically engineered, GMP-aligned benchtop platform designed for scalable bioprocessing applications in downstream purification of biomolecules—including monoclonal antibodies, viral vectors, plasmid DNA, and extracellular vesicles. Engineered around the fundamental hydrodynamic principle of tangential flow—where feed solution flows parallel to the membrane surface to minimize fouling—the STF system enables continuous concentration, diafiltration, buffer exchange, and size-based fractionation with high recovery and reproducible flux performance. Its architecture integrates real-time process analytics, closed-loop pressure regulation, and native compliance with FDA 21 CFR Part 11 requirements—making it suitable for both R&D labs validating purification workflows and QC environments supporting GLP/GMP-compliant manufacturing.

Key Features

• Fully domestic hardware stack: From custom microcontroller firmware to 316L stainless-steel peristaltic pump rollers and PES-housed pressure transducers—ensuring supply chain stability and long-term serviceability.
• Modular, split-frame mechanical design: Enables rapid reconfiguration between lab bench and ISO Class 5 cleanroom environments; supports seamless integration with single-use fluid paths including flat-sheet cassettes and hollow-fiber modules.
• Dual high-precision load cells: Integrated feed (0–6.2 kg, 0.1 g resolution) and permeate (0–20 kg, 0.1 g resolution) weighing systems enable gravimetric process control with ±1 g accuracy in constant-volume diafiltration mode.
• Real-time TMP regulation: Closed-loop control maintains transmembrane pressure within ±1 psi tolerance, with response time ≤60 seconds—critical for preserving shear-sensitive biologics during concentration.
• Embedded HUAWEI MateBook E controller (Intel Core i5 / 16 GB RAM / 1 TB SSD): Runs STF Workstation software natively; features deterministic USB-C and RS485 interfaces for synchronized data acquisition from all sensors and actuators.
• Sanitary fluid path: Luer-lock connections throughout; all wetted surfaces compatible with SIP (steam-in-place) protocols and validated cleaning-in-place (CIP) cycles using NaOH or ethanol.

Sample Compatibility & Compliance

The STF system accommodates sample volumes ranging from 10 mL to 5 L per run, supporting both low-throughput screening and pilot-scale process development. It is compatible with commercially available ultrafiltration (MWCO: 3–500 kDa) and microfiltration (pore size: 0.1–0.45 µm) membranes—including polyethersulfone (PES), regenerated cellulose (RC), and polyvinylidene fluoride (PVDF)—in cassette, spiral-wound, and hollow-fiber configurations. The system meets ISO 13485:2016 design control principles and adheres to ASTM F838-20 (bacterial retention testing) and USP <788> particulate matter standards when operated with certified single-use components. All electronic records—including method parameters, sensor logs, alarm events, and user actions—are stored with cryptographic hashing, immutable audit trails, and role-based access control compliant with 21 CFR Part 11 Subpart B.

Software & Data Management

The STF Workstation software provides a validated, browser-accessible interface for method creation, execution, and post-run analysis. It displays and logs in real time: feed/permeate flow rates, inlet/retentate/permeate pressures, TMP, conductivity (0–300 mS/cm, ±2% full scale), temperature, shear rate estimation, concentration factor, diafiltration volume, and cumulative process time. Users may define variable sampling intervals (1 sec–60 min), configure multi-step methods (e.g., hold → concentrate → diafilter → flush), and export raw CSV or PDF reports with digital signatures. Built-in data integrity safeguards include electronic signatures, automatic backup to network drives, and tamper-evident log files retained for ≥36 months.

Applications

• Monoclonal antibody (mAb) concentration and buffer exchange prior to chromatography
• Adeno-associated virus (AAV) vector purification and formulation
• Plasmid DNA polishing and endotoxin reduction
• Exosome isolation and enrichment from cell culture supernatants
• Process characterization studies under varying shear, TMP, and flux conditions
• Technology transfer support for scale-up to production-scale TFF skids

FAQ

What membrane formats are supported by the STF system?

The system accepts standard flat-sheet cassettes (with integrated feed/diafiltration ports) and hollow-fiber modules (with luer-compatible inlet/outlet manifolds). Custom adapters are available for proprietary cartridge formats.
Does the STF system support automated cleaning-in-place (CIP)?

Yes—via programmable pump sequences and conductivity monitoring; validated CIP protocols using 0.1–1.0 M NaOH or 20–30% ethanol can be saved and recalled as methods.
Can the system operate unattended overnight?

Yes—equipped with thermal overload protection, pressure-limiting valves, weight-based endpoint detection, and configurable email/SMS alerts via optional IoT gateway module.
Is remote monitoring and control possible?

Remote desktop access and secure HTTPS-based data streaming are enabled through the embedded Windows OS and STF Workstation’s RESTful API (available under NDA).
What validation documentation is provided?

Each unit ships with Factory Acceptance Test (FAT) report, IQ/OQ protocol templates, and a complete 21 CFR Part 11 compliance package—including electronic signature validation, audit trail verification, and cybersecurity assessment summary.