Stuart SA8 Variable-Speed Vortex Mixer

Overview

The Stuart SA8 Variable-Speed Vortex Mixer is an engineered laboratory mixing solution designed for precise, reproducible vortexing of liquid samples across a broad dynamic range. Utilizing eccentric orbital motion—where the platform rotates around a fixed axis with a 4.2 mm orbit diameter—the SA8 induces controlled turbulent flow within containers, enabling rapid homogenization, resuspension, and emulsification without introducing shear-sensitive degradation. Its operational principle relies on mechanical coupling between the motor-driven cam mechanism and the rubberized platform, ensuring consistent energy transfer regardless of load or container geometry. Designed for routine use in QC laboratories, academic research settings, and clinical diagnostics workflows, the SA8 delivers high repeatability under both intermittent and continuous duty cycles, supporting applications from DNA extraction buffer preparation to cell culture media reconstitution.

Key Features

• Variable speed control from 200 to 2500 rpm, calibrated for fine-grained adjustment via front-panel rotary dial
• Dual-mode operation: “Touch” mode initiates mixing only while pressure is applied to the activation pad; continuous mode maintains steady-state rotation until manually stopped
• Low-profile, die-cast metal chassis provides structural rigidity and minimizes parasitic vibration during high-speed operation
• Ergonomic height (78 mm) reduces operator fatigue during extended benchtop use and improves visual access to sample vessels
• Integrated mounting holes allow secure attachment of optional accessories—including universal clamps and vertical support stands—for unattended overnight mixing protocols
• IP31-rated enclosure ensures resistance to vertically falling drips and solid objects ≥2.5 mm, suitable for general laboratory environments with moderate humidity and incidental splashes

Sample Compatibility & Compliance

The SA8 accommodates a wide variety of standard labware through its modular accessory system. When paired with the SA8/1 Accessory Kit, it supports microplates (96-well format), conical tubes (0.2 mL to 15 mL), centrifuge tubes (up to 50 mL), Erlenmeyer flasks (up to 500 mL), and custom-drilled foam inserts for irregularly shaped vessels. All accessories are manufactured from non-reactive, autoclavable polymers compliant with ISO 10993-5 cytotoxicity standards. The mixer itself meets IEC 61010-1:2010 safety requirements for electrical equipment used in laboratory environments and carries CE marking for conformity with EU directives. While not certified for GMP manufacturing environments per se, its design supports GLP-compliant documentation practices through stable performance parameters and traceable operating conditions.

Software & Data Management

The SA8 operates as a standalone analog instrument with no embedded firmware or digital interface. Speed setting and mode selection are fully manual, eliminating software validation requirements and reducing potential failure points in regulated environments. This architecture aligns with FDA 21 CFR Part 11 principles for instruments where electronic records are not generated—ensuring that all operational states remain directly observable and auditable by personnel. For laboratories requiring integration into electronic lab notebooks (ELNs) or LIMS systems, external logging devices (e.g., USB data loggers with RPM-sensing capability) may be deployed in conjunction with the SA8’s consistent mechanical output.

Applications

• Resuspension of lyophilized reagents and bacterial pellets in molecular biology workflows
• Homogenization of immunoassay diluents and ELISA coating buffers
• Preparation of calibration standards for HPLC and mass spectrometry sample introduction
• Mixing of viscous solutions such as glycerol stocks, agarose gels, and polymer dispersions
• Uniform dispersion of nanoparticles in suspension-based nanotoxicology studies
• Routine quality control checks for viscosity consistency in pharmaceutical excipient batches

FAQ

Is the SA8 compatible with 15-mL conical tubes?
Yes—the SA8 platform accommodates 15-mL conical tubes when used with the rectangular foam insert included in the SA8/1 accessory kit.
Can the SA8 be operated inside a cold room at 4°C?
Yes—its wide input voltage range (90–240 V) and low power draw (20 W) ensure stable operation under ambient temperatures ranging from 5°C to 40°C, provided condensation is prevented.
Does the SA8 require periodic calibration?
No formal calibration is required; however, users should verify rotational speed accuracy annually using a handheld tachometer against the marked dial positions.
What is the expected service life under normal usage?
With proper maintenance—including periodic inspection of the rubber platform coupling and cleaning of ventilation grilles—the SA8 typically exceeds 10 years of daily laboratory use.
Is the SA8/1 accessory kit sold separately?
Yes—the SA8/1 kit is available as a distinct SKU and must be ordered separately from the base SA8 unit.