Stuart SRT9 & SRT9D 9-Roller Orbital Rotator Shaker

Overview

The Stuart SRT9 and SRT9D are precision-engineered 9-roller orbital rotator shakers designed for gentle yet highly effective mixing of sensitive biological and clinical samples. Unlike vortexers or orbital shakers that induce high-shear agitation, these instruments operate on a low-angle rolling principle—rotating sample tubes or bottles along a fixed 16 mm amplitude arc—to ensure homogeneous suspension without foaming, phase separation, or cellular damage. This makes them especially suitable for applications where gas entrainment must be minimized: whole blood anticoagulant mixing, serum separation, viscous polymer solutions, cell culture media reconstitution, and solid-liquid suspensions in diagnostic assay preparation. Both models feature a robust, corrosion-resistant chassis and are rated for continuous operation within controlled environments—including refrigerated storage units (down to +4 °C) and CO₂ incubators or bacterial growth chambers (up to +60 °C, ≤80% RH). Their compact footprint and quiet motor architecture support integration into biosafety cabinets, cold rooms, and automated lab workflows.

Key Features

• Nine independently aligned rollers provide uniform torque distribution and consistent rotational geometry across all sample positions—ensuring reproducible mixing performance even under full load (up to 10 kg total).
• SRT9 model delivers fixed-speed operation at 33 rpm via a simple toggle switch—ideal for standardized protocols requiring minimal user input and maximum operational reliability.
• SRT9D model offers digitally regulated speed control from 5 to 60 rpm in 1 rpm increments, with dual-range programmable timing: high-resolution mode (1 second to 90 minutes) and extended-duration mode (1 minute to 9999 minutes), supporting both short-term homogenization and overnight incubation-mixing cycles.
• Roller surfaces are constructed from chemically inert, autoclavable polypropylene; drip trays beneath each roller bank capture accidental overflow, simplifying decontamination and maintaining benchtop hygiene.
• Low-noise brushless DC motor and vibration-damped mounting system enable uninterrupted use in noise-sensitive environments such as core facilities, clinical labs, and shared research spaces.
• CE-marked and RoHS-compliant construction meets essential EU health, safety, and environmental protection requirements for laboratory equipment used in regulated settings.

Sample Compatibility & Compliance

The SRT9/SRT9D accommodates standard tube formats including 12–18 mm diameter glass or plastic test tubes, 15 mL and 50 mL conical centrifuge tubes, and flat-bottomed bottles up to 500 mL volume. Its low-shear rolling action preserves erythrocyte integrity during EDTA or citrate blood mixing—supporting CLSI H20-A2 and ISO 15189 preanalytical requirements. The unit’s thermal stability and sealed electronics allow direct placement inside validated incubators and cold rooms without compromising calibration or safety certification. For laboratories operating under Good Laboratory Practice (GLP) or ISO/IEC 17025 frameworks, the SRT9D’s digital timer logs timestamped start/stop events—enabling basic audit trail generation when paired with external documentation systems.

Software & Data Management

While the SRT9 operates without software interface, the SRT9D includes an embedded microcontroller with non-volatile memory that retains user-defined speed and timer settings after power cycling. No proprietary drivers or PC connectivity are required; all configuration is performed via intuitive front-panel membrane buttons and LED display. Although not FDA 21 CFR Part 11 compliant out-of-the-box, the device supports traceability when integrated with LIMS or ELN platforms via manual entry of run parameters and timestamps—particularly valuable in QC/QA workflows for pharmaceutical raw material testing or biobank sample processing.

Applications

• Clinical hematology: Anticoagulated whole blood mixing prior to hematocrit measurement or flow cytometry staining.
• Diagnostic assay prep: Homogenizing viscous mucus, synovial fluid, or stool suspensions for PCR-based pathogen detection.
• Biopharma R&D: Rehydrating lyophilized proteins or antibodies while minimizing aggregate formation.
• Microbiology: Maintaining aerobic suspension cultures of slow-growing organisms (e.g., Mycobacterium spp.) during antibiotic susceptibility testing.
• Forensic toxicology: Uniform extraction of solid-phase sorbents in urine drug screening workflows.

FAQ

Can the SRT9D be used inside a CO₂ incubator?

Yes—the unit is rated for continuous operation at temperatures up to +60 °C and relative humidity ≤80%, making it compatible with most standard CO₂ incubators when placed on stable, non-vibrating shelves.
Is the roller surface autoclavable?

The polypropylene rollers are autoclavable at 121 °C for 15 minutes; however, the main chassis and electronic components must remain outside sterilization cycles.
Does the SRT9D support external triggering or data export?

No—it lacks RS-232, USB, or Ethernet interfaces; all operation is self-contained and manually configured.
What maintenance is required?

Routine cleaning with 70% ethanol or isopropyl alcohol; periodic inspection of roller alignment and belt tension (if applicable); no scheduled lubrication or recalibration is needed.
Are replacement rollers available separately?

Yes—Stuart supplies OEM roller assemblies (Part No. SRT-ROLLER-KIT) and drip trays (Part No. SRT-DTRAY) for field replacement.