GLTlab SS-4 Low-Speed Magnetic Stirrer for Bacterial Culture Applications

Overview

The GLTlab SS-4 Low-Speed Magnetic Stirrer is an engineered solution designed specifically for gentle, sustained agitation in microbiological culture workflows. Unlike high-shear or rapid-mixing stirrers, the SS-4 operates within a precisely regulated 1–100 rpm range—optimal for maintaining aerobic homogeneity in bacterial suspensions without inducing shear stress that may compromise cell viability or alter metabolic activity. Its four independent stirring positions accommodate standard Erlenmeyer flasks (up to 3 L each), enabling parallel cultivation under consistent rotational conditions. The unit employs a brushless DC motor architecture, delivering stable torque output across the full speed range and eliminating carbon brush wear—a critical reliability factor for unattended overnight or multi-hour incubation protocols. Built for integration into controlled-environment labs, the SS-4 functions at ambient temperature only, avoiding thermal interference with external incubators or environmental chambers.

Key Features

• Four-channel independent stirring platform with individual speed control per position
• Ultra-low-speed precision regulation (1–100 rpm) with ±1 rpm repeatability
• Brushless DC motor ensuring >20,000-hour service life and silent, vibration-minimized operation
• Wi-Fi-enabled real-time monitoring and remote parameter adjustment via GLTlabLinks™ software
• Support for synchronized control of multiple SS-4 units from a single workstation interface
• Robust aluminum alloy housing with chemical-resistant coating for long-term durability in humid or reagent-exposed lab environments
• Non-slip silicone mat surface and adjustable magnetic coupling strength to prevent stir bar ejection during extended runs

Sample Compatibility & Compliance

The SS-4 accommodates standard borosilicate glass and polypropylene vessels ranging from 50 mL test tubes to 3 L Erlenmeyer flasks. It is compatible with PTFE- or PTFE-coated magnetic stir bars (diameters 8–15 mm, lengths 30–60 mm), including low-profile designs suitable for narrow-necked culture bottles. While the device itself does not provide active heating or cooling, its ambient-only operation ensures compliance with ISO 13485 and GLP-aligned workflows where thermal stability is externally managed (e.g., inside CO₂ incubators or temperature-controlled rooms). All electrical components meet IEC 61010-1 safety standards for laboratory equipment, and firmware supports audit-ready logging when used with GLTlabLinks™ under 21 CFR Part 11-compliant configuration (user authentication, electronic signatures, and immutable event logs).

Software & Data Management

GLTlabLinks™ is a cross-platform application (Windows/macOS/Linux) that enables secure, encrypted Wi-Fi communication with up to 16 SS-4 units simultaneously. The software records timestamped speed values, operational status, and runtime duration for each channel, exporting data in CSV and PDF formats suitable for QA documentation. Configurable alert thresholds trigger desktop notifications or email alerts upon speed deviation (>±3 rpm), unexpected shutdown, or connectivity loss. All data files include embedded metadata (unit ID, operator login, firmware version), supporting traceability requirements under ISO/IEC 17025 and internal quality management systems. No cloud storage is mandatory—the software operates fully on local networks to preserve data sovereignty and align with institutional IT security policies.

Applications

• Sustained oxygenation of Escherichia coli, Bacillus subtilis, and other aerobically cultured bacteria in shake-flask bioreactors
• Pre-incubation mixing of antibiotic susceptibility test media (e.g., Mueller-Hinton broth) prior to pour plating
• Gentle resuspension of cryopreserved bacterial stocks to minimize mechanical lysis
• Homogenization of viscous agar-based media during pre-pour equilibration
• Parallel preparation of calibration standards for microbial enumeration assays
• Long-duration enzymatic reactions requiring continuous but non-turbulent agitation

FAQ

Can the SS-4 be used inside a CO₂ incubator?

Yes—its ambient-only operation and sealed electronics allow safe placement inside standard CO₂ incubators (up to 95% humidity, 37°C), provided the unit remains outside the direct humidified chamber airflow path to prevent condensation ingress.
Is GLTlabLinks™ compatible with LIMS integration?

The software supports export of structured CSV logs with standardized column headers, enabling direct ingestion into common LIMS platforms via automated script or manual import; API access is available under enterprise licensing agreements.
What stir bar specifications are recommended for optimal performance at 5 rpm?

For reliable coupling below 10 rpm, use elliptical or capsule-shaped PTFE-coated stir bars (10 mm × 40 mm) with magnetic moment ≥ 15 mT·cm³—ensuring stable rotation even in high-viscosity media (e.g., 2% w/v agarose solutions).