Burrell Model 75 Wrist-Action Shaker

Overview

The Burrell Model 75 Wrist-Action Shaker is a precision-engineered laboratory shaker designed to replicate the gentle, elliptical motion of the human wrist—providing low-shear, non-turbulent mixing ideal for delicate biological suspensions, cell cultures, immunoassays, and solubility studies. Unlike orbital or reciprocating shakers, the Model 75 employs a true wrist-action mechanism that generates a smooth, sinusoidal arc with programmable angular displacement (0–15°), enabling precise control over agitation intensity without altering oscillation frequency (385 ±10% osc/min). This mechanical design minimizes foaming, particle aggregation, and shear-induced denaturation—critical for maintaining sample integrity in microbiology, clinical diagnostics, and pharmaceutical formulation development. The device features dual independent platforms, each supporting configurable clamp assemblies or tray-based loading, and is compatible with standard laboratory glassware including Erlenmeyer flasks (up to 2 L), separatory funnels, volumetric flasks, test tubes, and wide-mouth bottles.

Key Features

• Dual-platform architecture enables simultaneous processing of two independent sample sets under identical or differentiated amplitude settings
• Adjustable oscillation amplitude (1°–15° per side) via calibrated side-arm lever—no change in frequency required to modulate mixing energy
• Programmable timer with dual-mode operation: fixed-duration cycles (0–60 minutes) or continuous run mode with auto-shutoff on thermal overload
• Overload protection circuitry automatically de-energizes motor if current draw exceeds safe threshold—ensuring long-term reliability and compliance with IEC 61010-1 safety standards
• Modular clamp system supports multiple configurations: side-arm clamps (for 2 × 250 mL or 2 × 500 mL flasks), top-mounted trays (8 × 250 mL capacity), and USP -compliant silicone-oil dampened fixtures
• Robust cast-aluminum housing with vibration-dampening feet; CE-marked and RoHS-compliant construction

Sample Compatibility & Compliance

The Model 75 accommodates a broad range of container geometries—including conical, cylindrical, and tapered vessels—without requiring custom adapters. Its wrist-action kinematics ensure uniform suspension of low-density particles (e.g., yeast, algae, latex beads) and prevent sediment resuspension artifacts common in high-G orbital systems. Accessories meet material compatibility requirements for GMP environments: FDA-listed silicone elastomers (Shore A 40–50), borosilicate glass-compatible stainless-steel clamps, and dimethyl silicone oil fixtures validated per USP for sterile compounding workflows. While the base unit is not temperature-controlled, it integrates seamlessly with third-party incubator chambers rated for 4–37 °C operation—supporting ISO 13485-aligned QC protocols in biomanufacturing and clinical labs.

Software & Data Management

The Model 75 operates as a stand-alone analog instrument with no embedded firmware or digital interface. All operational parameters are set manually via front-panel controls, ensuring electromagnetic interference (EMI) immunity and eliminating software validation burdens under FDA 21 CFR Part 11. For laboratories requiring audit trails, optional external data loggers (e.g., Omega OM-DAQPRO-5300) can record runtime, power consumption, and ambient temperature via analog voltage outputs. Clamp configuration records and maintenance logs are maintained per GLP Annex 11 guidelines using paper-based or validated LIMS-integrated documentation systems.

Applications

• Cell culture passaging and reagent resuspension where minimal shear stress is essential
• Antibody-antigen binding kinetics in ELISA plate pre-incubation steps
• Extraction efficiency optimization for solid-phase microextraction (SPME) and liquid–liquid partitioning
• Stability testing of protein therapeutics under accelerated conditions (ICH Q5C)
• Environmental microbiology: MPN enumeration using serial dilution flasks
• Pharmaceutical quality control: dissolution profile verification per USP

FAQ

What is the maximum recommended load per platform?
The manufacturer specifies a maximum load of 3.6 kg (8 lbs) per platform when operating at full amplitude (15°). Exceeding this limit may compromise oscillation consistency and accelerate bearing wear.
Can the Model 75 be used inside a CO₂ incubator?
No—the base unit is not rated for humidified, high-CO₂ environments. However, it is compatible with externally mounted incubator enclosures that maintain temperature control while isolating electronics from corrosive atmospheres.
Are calibration certificates available for the oscillation frequency?
Yes—NIST-traceable calibration services are offered by authorized service centers using optical tachometry per ASTM E178, with documented uncertainty ≤ ±0.5% at 385 osc/min.
Does the shaker support GLP-compliant operation?
Yes—its analog control architecture eliminates electronic audit trail requirements. Full GLP adherence is achieved through documented maintenance schedules, operator training records, and clamp configuration logs per OECD GLP Principles Section 5.2.
What voltage options are supported beyond 220 V?
The Model 75 is configured at time of order for either 115 V / 60 Hz (North America) or 220–240 V / 50 Hz (EU/Asia); dual-voltage models are not available. Input voltage must match nameplate specification to avoid motor damage.