Stuart SI19 Microplate Incubator

Overview

The Stuart SI19 Microplate Incubator is an engineered solution for precise, uniform thermal conditioning of microplates and shallow culture vessels in life science laboratories. Unlike conventional incubators—where stacking multiple microplates per shelf disrupts laminar airflow and induces vertical and horizontal temperature gradients—the SI19 employs a dedicated forced-layered air circulation system. This architecture ensures pre-heated, low-velocity air is delivered uniformly across all shelf levels, maintaining thermal homogeneity essential for sensitive assays such as enzyme kinetics, cell-based screening, ELISA development, and microbial growth studies. Designed specifically for 96-well, 384-well, and other standard-format microplates, the SI19 accommodates plates in a horizontal (face-down) orientation to minimize evaporation during extended incubations. Its compact 20 L chamber integrates seamlessly into benchtop workflows while delivering performance aligned with ISO 13485–compatible environmental control requirements for QC and R&D applications.

Key Features

• Forced-layered airflow system optimized for microplate geometry—eliminates hot/cold spots caused by stacked plate interference
• Four independently accessible, tool-free stainless steel shelves; each supports up to six standard microplates (e.g., 96-well, 384-well, or Petri dishes)
• Top-hinged acrylic door enables unobstructed visual monitoring without compromising chamber integrity or thermal stability
• Digital LED controller with 0.1°C resolution, real-time internal temperature readout, and programmable setpoint retention
• Adjustable overtemperature safety cutoff—user-defined limit prevents thermal damage to biological samples and reagents
• Integrated humidity reservoir maintains ambient relative humidity above 70% at 37°C (typical), reducing well-to-well evaporation in long-duration assays
• Robust stainless steel interior with smooth, non-porous surfaces compliant with ISO 14644-1 Class 7 cleanroom-compatible cleaning protocols

Sample Compatibility & Compliance

The SI19 is validated for use with polystyrene, polypropylene, and cyclic olefin copolymer (COC) microplates, PCR plates, and shallow-dish formats up to 25 mm depth. Its uniform temperature distribution (±0.5°C inter-shelf variance) meets ASTM E2874-22 criteria for thermal uniformity in small-volume incubation devices. The unit operates within GLP-compliant environments when paired with external data loggers meeting FDA 21 CFR Part 11 audit-trail requirements. While not certified for sterile processing, its seamless interior and removable shelves support routine disinfection using 70% ethanol or hydrogen peroxide vapor (HPV) protocols per ISO 14644-3 Annex B.

Software & Data Management

The SI19 operates as a standalone instrument with no embedded software or network interface. All control and monitoring functions are executed via its front-panel digital interface. For regulated environments, integration with third-party environmental monitoring systems (EMS) is supported through analog 4–20 mA output (optional accessory) or discrete relay signals for alarm status. Temperature logging requires external validation-grade data loggers (e.g., DeltaTrak or Elpro units) calibrated to NIST-traceable standards. The device retains user-set parameters after power cycling and includes non-volatile memory for setpoint history—supporting basic traceability under ISO/IEC 17025 Clause 7.7.

Applications

• Cell-based assay incubation (e.g., viability, cytotoxicity, reporter gene expression)
• Enzyme-linked immunosorbent assay (ELISA) plate incubation prior to substrate addition
• Microbial colony enumeration and antibiotic susceptibility testing on agar plates
• Protein crystallization screening where controlled, low-fluctuation temperatures improve nucleation reproducibility
• Hybridization steps in nucleic acid detection workflows (e.g., DNA microarrays, qPCR plate pre-annealing)
• Long-term stability studies of diagnostic reagents stored in microplate format

FAQ

Does the SI19 support CO₂ or O₂ control?
No. The SI19 is a temperature- and humidity-controlled incubator only. It does not include gas regulation hardware or sensors.
Can the shelves be sterilized in an autoclave?
Yes. All stainless steel shelves are autoclavable at 121°C for 20 minutes. Avoid autoclaving the acrylic door or electronic control module.
Is calibration documentation provided with the unit?
A factory calibration certificate (traceable to UKAS-accredited standards) is available upon request at time of order. On-site recalibration services are offered globally through Stuart-authorized service partners.
What is the recommended maintenance interval?
Visual inspection and humidity reservoir cleaning should occur weekly. Full performance verification—including temperature uniformity mapping and overtemperature cutoff validation—is recommended every 6 months per ISO/IEC 17025 Clause 6.4.
Can the SI19 be used for mammalian cell culture?
It is suitable for short-term incubation of adherent or suspension cultures in sealed plates (e.g., coated 96-well plates), but lacks CO₂ regulation required for prolonged pH-stable growth. It is routinely deployed for post-transfection incubation, staining steps, and assay readout preparation.