MD99-2A Automated UV-Vis Chromatographic Fraction Collector System with PC-Based Data Acquisition

Overview

The MD99-2A Automated UV-Vis Chromatographic Fraction Collector System is a benchtop preparative liquid chromatography platform engineered for reproducible nucleic acid and protein purification under laboratory-scale conditions. It operates on the principle of size-exclusion, ion-exchange, or affinity chromatography—depending on column chemistry—and integrates real-time ultraviolet absorbance detection at four fixed wavelengths (220 nm, 254 nm, 280 nm, and 340 nm) to monitor elution profiles of biomolecules. The system employs a constant-flow peristaltic pump (HL-2) coupled with a dual-syringe gradient mixer (TH-500) to deliver precise, linear solvent gradients up to 1000 mL. Eluate is directed through an HD-3 UV detector and subsequently fractionated by the BS-100A programmable collector into 100 × 12 mL tubes, with timing resolution down to 1 second. All analog signals—including UV absorbance, pump status, and collection triggers—are digitized and synchronized via the HD-A PC acquisition module, enabling traceable, timestamped data capture compliant with basic GLP documentation requirements.

Key Features

• Four-wavelength fixed-band UV detection optimized for nucleic acid (260 nm proxy via 254/280 nm) and aromatic amino acid quantification (280 nm)
• Programmable fraction collection with ±0.5 s timer accuracy and tube-position indexing
• Adjustable flow rate control from 0.1 to 10 mL/min, suitable for analytical to semi-preparative column dimensions
• Modular architecture: Interchangeable columns (Φ1.0×40 cm, Φ1.6×50 cm, Φ2.5×60 cm) support diverse resin chemistries including Sephadex, DEAE, and Ni-NTA media
• Linear gradient generation with dual-reservoir mixing; no stepwise or curved profile capability
• HD-A acquisition interface provides native Windows-compatible drivers, real-time chromatogram rendering, baseline subtraction, peak integration, and export to CSV/TXT for third-party statistical packages (e.g., GraphPad Prism, MATLAB)
• No internal data storage: All acquired data reside exclusively on the user-supplied host PC, facilitating audit-ready folder structures and version-controlled backups

Sample Compatibility & Compliance

The MD99-2A accommodates aqueous and low-organic mobile phases (≤20% acetonitrile or methanol), making it suitable for desalting, buffer exchange, and purification of plasmid DNA, PCR products, recombinant proteins, and antibody fragments. It is not rated for high-pressure operation (>2 bar) or aggressive solvents (e.g., DMSO, chloroform). While the system itself does not carry CE, UL, or FDA 510(k) certification, its component-level design aligns with IEC 61010-1 safety standards for laboratory electrical equipment. UV lamp intensity stability meets ASTM E275-22 criteria for photometric repeatability in absorbance-based quantitation. Data acquisition workflows support manual metadata annotation (sample ID, operator, date/time stamp), forming a foundational layer for ISO/IEC 17025-compliant method validation when paired with documented SOPs.

Software & Data Management

The HD-A software suite runs natively on Windows 10/11 (64-bit) and requires no runtime licenses or cloud activation. It captures raw voltage outputs from the HD-3 detector at 10 Hz sampling frequency and applies configurable digital filtering to suppress pump pulsation artifacts. Chromatograms are rendered in real time with adjustable Y-axis scaling and overlay capability for comparative runs. Peak detection uses first-derivative thresholding; retention time and area-under-curve (AUC) values are exported with six decimal precision. Audit trails are maintained via Windows Event Log integration—system startup, parameter changes, and file saves generate timestamped entries. For regulated environments, users may implement supplemental 21 CFR Part 11 compliance through institutional IT policies (e.g., domain-based login, encrypted network shares, and periodic backup verification).

Applications

• Plasmid DNA purification following alkaline lysis and RNase A treatment
• Removal of unincorporated dNTPs and primers from PCR reaction mixtures
• Size-based separation of denatured proteins prior to SDS-PAGE or mass spectrometry
• Buffer exchange of monoclonal antibodies into formulation buffers using gel filtration media
• Small-scale isolation of His-tagged fusion proteins on immobilized metal affinity columns
• Teaching laboratories: Hands-on instruction in chromatographic theory, detector calibration, and fraction pooling strategies

FAQ

Is the MD99-2A compatible with HPLC-grade columns or high-pressure applications?
No. This system is designed for low-pressure gravity-fed or peristaltic-pump-driven chromatography only. Maximum recommended backpressure is 1.5 bar. HPLC or UHPLC columns are not supported.
Can gradient shape be customized beyond linear profiles?
No. The TH-500 mixer supports linear gradients only. Nonlinear (concave/convex) or multi-step gradients require external hardware or manual solvent switching.
Does the HD-A software support automated peak identification or calibration curve generation?
Basic peak detection and integration are included. Quantitative calibration (e.g., standard curves) must be performed externally using spreadsheet or statistical software.
What operating systems are officially supported?
Windows 10 and Windows 11 (64-bit editions only). No macOS or Linux drivers are provided.
Is service and technical support available outside mainland China?
Warranty and remote diagnostics are administered globally through authorized distribution partners. On-site service requires advance coordination and may incur travel fees outside Asia-Pacific regions.