Shanghai TH-500 Gradient Mixer
| Origin | Shanghai, China |
|---|---|
| Manufacturer Type | Authorized Distributor |
| Origin Category | Domestic (PRC) |
| Model | TH-500 |
| Price | USD 225 |
| Dimensions (W×D×H) | 291 × 180 × 205 mm |
| Gradient Volume Capacity | 1000 mL |
| Gradient Profile | Linear Only |
| Flow Rate | Adjustable via dual-syringe pump mechanism |
| Liquid Level Balancing | Passive gravity-coupled dual-reservoir design |
Overview
The Shanghai TH-500 Gradient Mixer is a precision-engineered laboratory device designed for the controlled generation of linear concentration gradients in liquid-phase chromatographic and electrophoretic applications. It operates on the principle of passive gravity-driven flow coupling between two independently adjustable reservoirs — one containing concentrated solution (e.g., buffer A) and the other diluent or alternative buffer (e.g., buffer B). By maintaining synchronized liquid level descent across both chambers via balanced siphon geometry and calibrated outlet orifices, the TH-500 ensures stable volumetric mixing ratios over time. Unlike motorized gradient formers with programmable profiles, this unit delivers reproducible linear gradients solely through mechanical design optimization, making it particularly suited for routine column equilibration, gel electrophoresis sample loading, and educational demonstrations where simplicity, reliability, and cost-efficiency are prioritized over multi-segment or nonlinear gradient programming.
Key Features
- Stable dual-reservoir architecture with integrated level-balancing siphon channels to minimize head-pressure variation during gradient formation
- Manually adjustable flow control valves for independent regulation of output flow rate and gradient slope
- 1000 mL total gradient volume capacity — sufficient for standard analytical and preparative-scale separations
- Compact footprint (291 × 180 × 205 mm) optimized for benchtop integration alongside UV detectors, fraction collectors, or electrophoresis rigs
- Chemically resistant body construction compatible with common aqueous buffers, ethanol/water mixtures, and low-concentration organic solvents
- No electrical components or power supply required — fully passive operation enhances safety and eliminates electromagnetic interference
Sample Compatibility & Compliance
The TH-500 is intended for use with non-hazardous, low-viscosity aqueous and semi-aqueous solutions typically employed in classical column chromatography (e.g., ion exchange, gel filtration), native PAGE, and isoelectric focusing setups. It is not rated for high-pressure applications, volatile organic solvents (e.g., acetonitrile, chloroform), or corrosive reagents such as strong acids (>2 M HCl) or alkalis (>1 M NaOH). While the device itself carries no formal ISO/IEC 17025 or FDA 21 CFR Part 11 certification (as it performs no measurement or data logging), its mechanical design conforms to general laboratory equipment safety guidelines per IEC 61010-1:2010. Users implementing the TH-500 in regulated environments (e.g., QC labs under GLP or GMP) are advised to establish in-house operational qualification (OQ) protocols including flow rate linearity verification and gradient reproducibility testing at defined timepoints.
Software & Data Management
The TH-500 Gradient Mixer is a standalone analog instrument with no embedded firmware, digital interface, or software dependency. Gradient execution is fully manual and visually monitored; users record start/end times, flow rates, and collected fractions using external lab notebooks or LIMS-integrated documentation systems. For traceability in validated workflows, laboratories commonly pair the TH-500 with third-party peristaltic pumps equipped with pulse-output signals or integrate it into larger chromatography systems via analog voltage-controlled flow regulators. No proprietary drivers, SDKs, or cloud connectivity are provided or supported.
Applications
- Preparative and analytical column chromatography requiring stepwise or continuous linear salt or pH gradients
- Native polyacrylamide gel electrophoresis (PAGE) for protein complex analysis
- Isotachophoresis and isotonic focusing methods relying on stable conductivity gradients
- Calibration of gradient detection systems (e.g., conductivity or UV absorbance monitors)
- Teaching laboratories demonstrating fundamental principles of solution mixing kinetics and diffusion-limited blending
- Low-budget core facilities seeking robust, maintenance-free gradient generation without reliance on microprocessor-based controllers
FAQ
Can the TH-500 generate nonlinear or segmented gradients?
No. The TH-500 is mechanically constrained to produce only linear gradients due to its fixed-orifice, gravity-fed dual-reservoir configuration.
What materials are in contact with the fluid path?
Reservoirs and tubing interfaces are constructed from borosilicate glass and food-grade silicone rubber; all wetted parts are autoclavable at 121°C for 20 minutes.
Is calibration required before use?
Yes — users must perform initial flow rate verification using graduated cylinders and stopwatch timing, especially when switching between buffer systems with differing densities or viscosities.
Does the unit include tubing and connectors?
Standard delivery includes two 1.5 m lengths of PTFE-compatible silicone tubing (4 mm ID), two barbed fittings, and two reservoir caps with integrated air vents.
Can it be used with HPLC systems?
Only in low-pressure (<5 psi) configurations; it is not compatible with high-pressure LC pumps or inline degassers without external pressure regulation.
