DLAB CT4-Pro 4°C Constant-Temperature Cooling Block

Overview

The DLAB CT4-Pro 4°C Constant-Temperature Cooling Block is a compact, microprocessor-controlled thermal management device engineered for precise, stable, and reproducible low-temperature incubation of biological samples in laboratory workflows. Unlike conventional refrigerated centrifuges or cold rooms, the CT4-Pro employs solid-state Peltier thermoelectric cooling technology to maintain a fixed, highly uniform 4°C environment—optimized for applications requiring strict thermal consistency without active refrigerant-based compression cycles. Its design targets critical pre-analytical steps where transient temperature excursions compromise sample integrity: enzymatic reaction quenching, DNA fragment stabilization prior to electrophoresis, serum coagulation kinetics, and short-term storage of PCR reagents or antibody solutions. The unit achieves thermal equilibrium from ambient (25°C) to 4°C in under 10 minutes and sustains ±0.3°C spatial uniformity across the entire block surface—verified per ISO/IEC 17025-aligned internal calibration protocols.

Key Features

• Peltier-based thermoelectric cooling system delivering rapid, oil-free, vibration-free 4°C stabilization with no condensation risk on sample tubes
• Integrated microcontroller with real-time PID feedback loop ensuring ±0.3°C temperature uniformity across all positions (tested at 9-point grid per ASTM E2202)
• Magnetic module interface enabling tool-free, repeatable attachment of interchangeable aluminum or stainless-steel blocks—compatible with 0.2 mL, 0.5 mL, 1.5 mL, and 2.0 mL tube formats
• Multi-color LED status display (green = standby, blue = active cooling, amber = calibration mode, red = over-temperature alert) for unambiguous operational feedback
• Built-in temperature deviation correction algorithm allowing user-initiated offset calibration against NIST-traceable reference probes
• Compact footprint (200 × 235 × 120 mm) and lightweight chassis (3.3 kg) optimized for benchtop integration in biosafety cabinets, laminar flow hoods, or automated liquid handling workcells
• Over-temperature protection circuitry compliant with IEC 61010-1:2010 safety standards, automatically disabling heating elements if sensor fault or thermal runaway is detected

Sample Compatibility & Compliance

The CT4-Pro accommodates standard conical, round-bottom, and PCR strip-compatible tube geometries without mechanical clamping or pressure-induced deformation. Its passive thermal mass distribution ensures minimal thermal gradient between peripheral and central wells—critical for quantitative assays sensitive to localized warming (e.g., qPCR master mix stability). The device meets essential regulatory prerequisites for GLP-compliant laboratories: it supports audit-ready temperature log export via optional RS-232 interface (firmware v2.1+), maintains traceable calibration records per ISO/IEC 17025 requirements, and operates within FDA 21 CFR Part 11–compatible data integrity frameworks when integrated with validated LIMS platforms. All materials in contact with sample carriers comply with USP Class VI biocompatibility standards and are free of phthalates and heavy metals per RoHS Directive 2011/65/EU.

Software & Data Management

While the CT4-Pro operates as a standalone instrument with intuitive front-panel controls, its embedded firmware (v2.1 and later) enables ASCII-formatted temperature logging via TTL-level serial output. When connected to a host PC running DLAB’s optional LogView Pro utility (Windows/macOS), users can generate time-stamped CSV reports containing timestamped block temperature, setpoint deviation, and operational status flags—formatted for direct import into ELN systems such as LabArchives or Benchling. Audit trails include operator ID entry (via keyboard emulation), calibration event timestamps, and firmware version verification—all retained in non-volatile memory with write-protection enabled by default. No cloud connectivity or proprietary drivers are required; communication adheres strictly to ANSI X3.27-1989 serial protocol standards.

Applications

• Stabilization of heat-labile enzymes (e.g., restriction endonucleases, ligases) during benchtop setup prior to reaction initiation
• Controlled serum coagulation at 4°C for clot retraction studies and fibrinogen quantification (per CLSI H21-A5 guidelines)
• Pre-chilling of electrophoresis loading buffers and DNA ladders to minimize band diffusion during gel loading
• Short-term holding of extracted nucleic acids during multi-step purification workflows (e.g., silica-membrane column elution to quantification)
• Temperature-sensitive reagent conditioning in ELISA plate preparation—particularly for conjugated antibodies prone to aggregation above 8°C
• Support of ISO 15189-accredited clinical microbiology labs performing cold-enrichment protocols for Listeria monocytogenes isolation

FAQ

Does the CT4-Pro support variable temperature setpoints?
No. The CT4-Pro is engineered exclusively for fixed 4°C operation to maximize thermal stability, energy efficiency, and long-term reliability—avoiding the complexity and precision trade-offs inherent in wide-range thermoelectric units.
Can the unit be operated inside a CO₂ incubator?
No. The CT4-Pro requires ambient air circulation for Peltier heat dissipation and is rated only for environments between 5–40°C and <80% RH. Enclosed humidified incubators exceed its environmental specifications.
Is third-party calibration certification available?
Yes. DLAB provides optional UKAS-accredited calibration certificates (traceable to NPL standards) upon request, including as-found/as-left data, uncertainty budgets, and ISO/IEC 17025 compliance statements.
What maintenance is required?
None beyond periodic cleaning of the aluminum heat sink fins with dry compressed air. The solid-state Peltier module has no moving parts or consumables and carries a 36-month limited warranty.
How does the magnetic module system ensure positional repeatability?
Each block contains embedded neodymium magnets aligned to ISO 2768-mK tolerance; insertion force exceeds 12 N, preventing lateral shift during vortexing or robotic arm handling—validated per IEC 60068-2-64 shock testing.