Grant PTR-25 Vertical Rotational Mixer

Overview

The Grant PTR-25 Vertical Rotational Mixer is an engineered solution for gentle, uniform end-over-end mixing of liquid samples in tubes and small vessels. Based on the principle of controlled 360° vertical rotation, it induces laminar, low-shear motion ideal for delicate biological suspensions where sedimentation, phase separation, or aggregation must be avoided. Unlike orbital shakers or vortex mixers, the PTR-25 delivers consistent tumbling without introducing air bubbles or mechanical stress—critical for hybridization assays, cell suspension maintenance, magnetic bead-based separations, and anticoagulant-free blood handling. Its compact footprint, low-voltage DC operation (12 V), and thermal stability across +4 °C to +40 °C make it uniquely suited for integration into cold rooms, incubators, and controlled-environment cabinets without compromising safety or performance.

Key Features

• Programmable timer with audible alert and auto-shutdown (1 minute to 24 hours)
• Precise speed control from 5 to 30 rpm via calibrated rotary dial
• True 360° vertical rotation axis ensuring complete sample inversion per cycle
• Robust, space-saving chassis constructed from chemically resistant ABS and reinforced polymer
• Low-power 12 V DC operation—eliminates mains voltage hazards in humid or temperature-controlled enclosures
• Integrated LED display for real-time monitoring of elapsed time and set parameters
• Standard 22-position platform accommodating Ø15 mm tubes (1.5–15 mL); compatible with optional multi-format accessories

Sample Compatibility & Compliance

The PTR-25 supports a wide range of primary sample containers used in molecular biology and clinical workflows, including polypropylene and glass test tubes (Ø10–15 mm), microcentrifuge tubes (1.5–15 mL), and small-volume PCR strips. Its non-vibratory, gravity-driven mixing mechanism preserves cell viability during prolonged suspension and avoids disruption of fragile complexes such as DNA-protein hybrids or antibody-coated magnetic beads. The device complies with IEC 61010-1:2010 for laboratory electrical equipment safety and meets EN 61326-1:2013 electromagnetic compatibility requirements. While not certified for GMP production environments, its design supports GLP-aligned documentation practices—including traceable parameter settings and manual log entries—making it suitable for QC labs, academic core facilities, and diagnostic R&D settings operating under ISO/IEC 17025 or CLIA guidelines.

Software & Data Management

The PTR-25 operates as a standalone analog-digital hybrid instrument with no embedded firmware or network interface. All operational parameters are set manually via front-panel controls; no software installation, driver dependencies, or cloud connectivity are required. This architecture ensures long-term reliability, immunity to OS updates or cybersecurity vulnerabilities, and full auditability of user-defined protocols. For laboratories requiring electronic recordkeeping, external timestamped logs can be generated using standard lab notebook systems or LIMS-integrated workflows. The absence of digital control logic means no 21 CFR Part 11 compliance burden—though users may implement procedural controls (e.g., dual-operator verification, printed parameter tags) to satisfy internal QA requirements.

Applications

• Nucleic acid hybridization (e.g., Southern/Northern blot pre-hybridization washes)
• Maintenance of adherent and suspension cell cultures during transport or short-term storage
• Homogenization of viscous lysates or tissue homogenates prior to centrifugation
• Binding and elution steps in magnetic bead-based immunoassays and nucleic acid purification kits
• Prevention of clot formation in whole blood or plasma samples during refrigerated transit
• Conjugation reactions involving antibodies, enzymes, or nanoparticles requiring slow, continuous agitation
• Equilibration of pH-sensitive buffers or reagent stocks prior to analytical use

FAQ

Can the PTR-25 be used inside a CO₂ incubator?
Yes—the unit’s 12 V DC power input, sealed electronics, and absence of heat-generating components allow safe operation in standard humidified CO₂ incubators (up to 40 °C, ≤95% RH), provided proper cable routing and ventilation are maintained.
Is the rotation speed digitally adjustable or stepwise?
Speed is continuously variable between 5 and 30 rpm via a calibrated analog dial; no discrete steps or digital increments are enforced.
What is the maximum tube diameter supported by the standard platform?
The included PRS-22 platform accommodates tubes up to Ø15 mm; optional platforms support Ø11 mm (PRSC-18) or mixed formats including 50 mL tubes (PPRS4-12).
Does the mixer generate measurable vibration that could affect adjacent sensitive instruments?
No—its balanced rotating arm and low-inertia drive produce negligible transmitted vibration (<0.05 mm/s RMS at 1 m distance), making it compatible with balances, microscopes, and other precision instruments in shared benchtop environments.
Can the timer be bypassed for continuous operation?
No—the timer is mandatory and non-defeatable; after reaching the preset duration, the unit halts automatically and emits an audible tone—ensuring protocol adherence and energy efficiency.