Cytiva ÄKTA™ pure micro Chromatography System
| Brand | Cytiva |
|---|---|
| Origin | Sweden |
| Model | ÄKTA™ pure micro |
| Purification Principle | Gel Filtration Chromatography (GFC) |
| Gradient Type | Linear Gradient |
| Flow Rate Range | 0.001–25 mL/min |
| Flow Accuracy | ±1.2% (absolute), RSD <0.5% (0.25–25 mL/min, <3 MPa, 0.8–2 cP) |
| UV Detection Range | 190–700 nm (multi-wavelength) |
| Conductivity Range | 0.01–999.99 mS/cm |
| Optional pH Sensor | 0–14 pH, ±0.1 pH (pH 2–12) |
| Pressure Range | 0–20 MPa |
| Solvent Compatibility | Compatible with 1 mol/L NaOH and 2 mol/L NaCl for ≥3 h in-place cleaning |
| Internal System Volume | As low as 18 µL (with micro kit) |
| Microfluidic Components | 0.8 µL injection valve, 2.6 µL UV flow cell, 5.4 µL conductivity cell, 0.7 µL outlet valve, 0.6 mL mixer, tubing ID: 0.13 mm or 0.25 mm |
Overview
The Cytiva ÄKTA™ pure micro Chromatography System is an engineered solution for high-resolution, low-volume biomolecule purification—specifically optimized for structural biology workflows where sample quantity is severely constrained. Built upon the proven architecture of the ÄKTA™ platform and controlled by UNICORN™ 7 software, this system implements gel filtration chromatography (GFC) using precise fluidic control and ultra-low dead-volume hardware to maximize recovery, resolution, and reproducibility from microliter-scale samples. Its design directly addresses the stringent purity, homogeneity, and concentration requirements of cryo-electron microscopy (cryo-EM), nuclear magnetic resonance (NMR), and X-ray crystallography—three primary techniques for atomic-resolution structure determination. Unlike conventional preparative systems, the ÄKTA™ pure micro minimizes band broadening through sub-microliter internal volumes across all critical path components, enabling sharp peak elution, improved separation of closely migrating species (e.g., protein isoforms or oligomeric states), and reduced dilution of precious material.
Key Features
- Ultra-low system internal volume: down to 18 µL when equipped with the micro purification kit, minimizing sample dispersion and preserving concentration integrity.
- Microfluidic detection modules: 2.6 µL UV flow cell (190–700 nm multi-wavelength), 5.4 µL conductivity cell (0.01–999.99 mS/cm), and optional pH sensor (0–14, ±0.1 pH units within pH 2–12).
- Precision flow control: programmable linear gradients over 0.001–25 mL/min with ±1.2% absolute accuracy and RSD <0.5% under defined viscosity and pressure conditions.
- High-pressure capability: operational up to 20 MPa, supporting both standard size-exclusion and high-resolution ion-exchange applications with Capto™ HiRes columns.
- Integrated F9-T dual-plate fraction collector with micro-droplet dispensing: enables automated collection into 96- or 384-well plates at volumes as low as 8 µL per fraction, with drop-synchronization to prevent cross-contamination during tube switching.
- ALIAS™ automated micro-sampler compatibility: supports 1 µL–10 mL injections with <60 s cycle time, refrigerated sample storage (down to 4°C), and full I/O-box E9 integration for synchronized UNICORN™ control.
Sample Compatibility & Compliance
The ÄKTA™ pure micro accommodates a wide range of biologics—including monoclonal antibodies, membrane proteins, viral capsids, and protein complexes—across multiple chromatographic modes. Its solvent compatibility includes aqueous buffers, chaotropes, and organic modifiers such as acetonitrile, permitting method transfer from analytical to micro-preparative scales. The system is validated for use with Cytiva’s Superdex™ Increase (8.6 µm particles) and Capto™ HiRes (9 µm particles) prepacked columns, including 3.2/300 GL (4–50 µL load), 5/150 GL (4–50 µL rapid screening), and 10/300 GL (25–500 µL prep/characterization) formats. All hardware materials comply with ISO 10993–1 for biocompatibility, and the system supports audit trails, electronic signatures, and data integrity features required under FDA 21 CFR Part 11 and EU Annex 11 when configured with UNICORN™ 7 in GxP mode.
Software & Data Management
UNICORN™ 7 serves as the unified control, method development, and data analysis environment for the ÄKTA™ pure micro. Its intuitive drag-and-drop method editor supports rapid protocol generation for GFC, IEX, and multimodal workflows. Real-time interactive flowpath visualization, column logging with barcode-assisted tracking, and integrated performance metrics (e.g., HETP, asymmetry, resolution between peaks) ensure traceability and method robustness. Results analysis leverages tiled overlay views, variable-based filtering, and export-ready reports compliant with GLP/GMP documentation standards. UNICORN™ Online—a browser-based remote monitoring extension—enables secure, zero-install access to live runs, historical data, and instrument status from any networked device. My Instruments provides centralized fleet visibility across laboratories, including alarm status, active users, and method execution history.
Applications
The system is routinely deployed in academic and industrial structural biology labs for:
- Cryo-EM sample preparation: isolating monodisperse, aggregation-free protein complexes from limited expression yields (e.g., <50 µg).
- NMR sample polishing: removing aggregates, fragments, or nucleic acid contaminants prior to isotopic labeling and spectral acquisition.
- X-ray crystallography feedstock refinement: achieving >95% homogeneity and defined oligomeric state for successful crystallization trials.
- Biophysical characterization: coupling SEC-MALS or SEC-DLS for native mass and hydrodynamic radius determination on sub-100 µL injections.
- Process development scouting: evaluating column alternatives, buffer conditions, or gradient slopes with minimal reagent consumption.
FAQ
Can the ÄKTA™ pure micro be upgraded from an existing ÄKTA™ pure 25 M?
Yes—the Cytiva Micro Purification Kit allows field conversion of ÄKTA™ pure 25 M systems to micro-capability, including micro-valves, low-volume detectors, fine-bore tubing (0.13 mm ID), and 10 µL/50 µL sample loops.
Is the system compatible with regulatory-compliant environments?
When operated with UNICORN™ 7 in audit-trail-enabled mode and connected to a validated network infrastructure, the system meets FDA 21 CFR Part 11 and EU GMP Annex 11 requirements for electronic records and signatures.
What column formats are supported for micro-scale separations?
Superdex™ Increase 3.2/300 GL (4–50 µL), Superose™ 6 Increase 3.2/300 GL, and Capto™ HiRes 5/50 columns are fully validated and recommended for optimal micro-purification performance.
Does the system support real-time pH monitoring during runs?
Yes—optional pH sensors integrate seamlessly into the flow path and are fully controllable and logged via UNICORN™ 7, with calibration traceability and temperature compensation.
How is carryover minimized during automated micro-injection?
The ALIAS™ autosampler employs dual-stage needle wash (aqueous + organic), positive-pressure purging, and programmable air-gap aspiration to achieve <0.001% carryover across 1 µL–10 mL injection volumes.
