Burrell Model 95 Variable Speed Wrist Action Shaker

Overview

The Burrell Model 95 Variable Speed Wrist Action Shaker is an engineered solution for laboratories requiring precise, reproducible, and physiologically relevant mixing—particularly where gentle yet effective suspension, solubilization, or homogenization of biological, clinical, or chemical samples is essential. Unlike orbital or reciprocating shakers, the Model 95 replicates the natural swirling motion of manual wrist agitation through a patented wrist-action mechanism. This motion generates a low-shear, elliptical orbital path with controlled angular displacement—mimicking the biomechanics of hand-held flask swirling while eliminating operator variability and fatigue. The device operates at ambient temperature and is optimized for applications demanding consistent fluid dynamics without thermal perturbation or mechanical stress to sensitive cells, proteins, or particulates.

Key Features

• True Wrist Action® Mechanism: Patented cam-and-linkage system delivers a smooth, continuous 0–15° arc oscillation—ensuring uniform vortex formation and minimal splashing across all vessel sizes and fill levels.
• Variable Speed Control: Digital speed dial enables fine-tuned adjustment from 0 to 450 oscillations per minute (osc/min), calibrated to ±10% accuracy at maximum setting; ideal for method optimization across diverse sample viscosities and densities.
• Dual-Platform Architecture: Equipped with two independently configurable platforms (BB configuration: 8 standard clamp positions), supporting parallel processing of heterogeneous sample sets without cross-contamination risk.
• Programmable Timer: Built-in mechanical timer permits discrete run durations from 1 to 60 minutes or indefinite continuous operation—fully compatible with unattended overnight protocols under GLP-compliant lab conditions.
• Modular Build-Up System: Designed for long-term scalability: users may upgrade from base Model 75 to Model 95, or expand capacity via optional side arms, top platforms, and SUREGRIP™ clamping accessories—all retaining mechanical and electrical interoperability.
• Rugged Construction: Housing fabricated from powder-coated steel and reinforced aluminum alloy; vibration-damped feet ensure stable operation on standard laboratory benches even at maximum amplitude and load.

Sample Compatibility & Compliance

The Model 95 accommodates a wide range of common laboratory vessels—including Erlenmeyer flasks (125 mL × 10, 250/300 mL × 8, or 500 mL × 6), separatory funnels, specimen jars, and graduated cylinders—when secured with Burrell’s standardized SUREGRIP™ finger-tight clamps. Its low-shear profile makes it suitable for cell culture maintenance, antigen-antibody incubation, blood bank serology testing, dissolution profiling (per USP ), and reagent reconstitution where bubble formation or foaming must be minimized. The unit complies with CE marking requirements (2014/30/EU EMC Directive and 2014/35/EU LVD Directive) and meets IEC 61010-1 safety standards for laboratory electrical equipment. While not intrinsically temperature-controlled, its ambient-only operation aligns with ISO/IEC 17025 clause 5.4.2 for environmental condition monitoring in accredited testing labs.

Software & Data Management

The Model 95 is a standalone electromechanical instrument with no embedded microprocessor or digital interface; therefore, it does not generate electronic audit trails, export data logs, or support FDA 21 CFR Part 11-compliant user authentication. However, its mechanical timer and analog speed control provide deterministic, tamper-resistant operation—advantageous in regulated environments where simplicity, traceability, and failure-mode transparency are prioritized over connectivity. For laboratories implementing electronic lab notebooks (ELNs) or LIMS integration, operational parameters (speed, duration, platform loading) are manually recorded per SOP, maintaining full compliance with GLP documentation requirements. Calibration verification can be performed using external tachometers and stopwatch timing—procedures documented in Burrell’s Technical Bulletin TB-95-01.

Applications

• Immunohematology: Gentle mixing of blood samples during antibody screening and identification (e.g., ISBT-recommended 15° arc agitation).
• Microbiology: Resuspension of lyophilized cultures, preparation of serial dilutions, and biofilm dispersion assays requiring non-turbulent shear profiles.
• Pharmaceutical QC: USP-compliant dissolution media conditioning and tablet disintegration test sample agitation.
• Environmental Testing: Extraction of analytes from solid-phase matrices (e.g., soil, sediment) using solvent-based shaking protocols per EPA Method 3510C.
• Protein Biochemistry: Low-shear reconstitution of lyophilized enzymes and antibodies to preserve tertiary structure integrity.
• Education & Training: Demonstrating kinetic mixing principles and validating manual technique equivalence in undergraduate and clinical training labs.

FAQ

What distinguishes “Wrist Action®” from orbital or reciprocating shaking?
Wrist Action® produces a true elliptical, low-angle (0–15°) oscillation that simulates human wrist motion—resulting in laminar fluid movement and reduced foam generation compared to high-shear orbital systems.
Can the Model 95 accommodate custom fixtures or third-party clamps?
Yes—Burrell’s universal mounting interface supports ISO-standard accessory rails; however, only SUREGRIP™ clamps are validated for load distribution and torque consistency at full 450 osc/min.
Is calibration required before first use?
No factory calibration is needed; however, users should verify oscillation frequency with a handheld tachometer and confirm timer accuracy against a certified stopwatch prior to critical application deployment.
What is the maximum permissible load per platform?
At rated speed (450 ±10% osc/min), total distributed load must not exceed 4.5 kg (10 lb) per platform—regardless of vessel count—to maintain mechanical stability and amplitude fidelity.
Does the shaker include overload or thermal protection?
Yes—the motor incorporates a self-resetting thermal cutout; sustained operation beyond 60 minutes at >400 osc/min may trigger intermittent shutdown until cooldown is achieved.