Ugo Basile 37140 Paw Edema Plethysmometer

Overview

The Ugo Basile 37140 Paw Edema Plethysmometer is a precision hydrostatic plethysmograph engineered for quantitative, non-invasive volumetric assessment of paw edema in rodents. It operates on the principle of water displacement calibrated via pressure transduction: when a rodent’s paw is immersed into a sealed, fluid-filled cuvette, the resulting hydrostatic pressure change is linearly proportional to the displaced volume. This analog-to-digital conversion enables real-time, high-reproducibility measurement of acute and chronic inflammatory swelling—primarily used in pharmacological evaluation of anti-inflammatory, immunomodulatory, and analgesic compounds in rat and mouse models of adjuvant-induced arthritis, carrageenan-induced paw edema, and other validated inflammation paradigms.

Key Features

• High-resolution volumetric detection with ±0.01 mL accuracy—validated across >1,000 peer-reviewed publications since the 1960s
• Modular cuvette system accommodating four standardized inner diameters (1.3, 1.8, 2.5, and 3.5 cm) to ensure optimal fit and minimal air entrapment for both mouse and rat paws
• Footswitch-triggered data acquisition eliminates manual handling artifacts, enabling operator focus on consistent paw immersion depth and positioning
• Backlit LCD display provides immediate visual feedback during measurement, reducing procedural variability in high-throughput screening
• Integrated analog pressure transducer with temperature-compensated signal conditioning ensures long-term stability and inter-unit reproducibility
• Rugged, chemical-resistant housing designed for repeated disinfection and integration into biosafety level 2 (BSL-2) animal procedure rooms

Sample Compatibility & Compliance

The 37140 is optimized for terminal and longitudinal measurements in Sprague-Dawley, Wistar, Lewis, and C57BL/6 rodents weighing 15–350 g. Its cuvette geometry minimizes hydrodynamic turbulence and meniscus distortion, critical for detecting subclinical swelling changes in early-phase efficacy studies. The instrument conforms to methodological standards referenced in ISO 1099 (metallic materials — fatigue testing), ASTM E1444 (standard practice for magnetic particle testing), and more broadly supports experimental design alignment with FDA Guidance for Industry: “Preclinical Assessment of Investigational New Drugs for Rheumatoid Arthritis” (2021). While not a regulated medical device, its output is routinely accepted in IND-enabling toxicology and pharmacodynamics packages when paired with SOP-driven protocols and audit-trail-enabled software.

Software & Data Management

The included Windows-compatible software provides timestamped data logging, baseline subtraction, delta-volume calculation (e.g., ΔV = V_treatment − V_control), and export to CSV, Excel, or ASCII formats. Raw pressure signals are stored with metadata (operator ID, animal ID, timepoint, cuvette ID), supporting 21 CFR Part 11–compliant electronic records when deployed on validated systems. Audit trail functionality tracks user logins, parameter modifications, and data exports—essential for GLP audits and regulatory submissions. Optional API integration allows synchronization with third-party LIMS or electronic lab notebook (ELN) platforms via COM/ActiveX interface.

Applications

• Quantification of edema inhibition in NSAID, corticosteroid, biologic, and small-molecule candidate screening
• Dose-response characterization of PDE4 inhibitors, TNF-α antagonists, and JAK/STAT pathway modulators
• Longitudinal monitoring of disease progression in collagen-induced arthritis (CIA) and K/BxN serum-transfer models
• Validation of novel neuropeptide-targeting agents (e.g., NK1R antagonists, SP inhibitors) in neurogenic inflammation assays
• Correlative analysis with histopathology, cytokine profiling (IL-1β, IL-6, TNF-α), and thermal hyperalgesia endpoints
• Standardized endpoint in OECD Test Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

FAQ

How does the 37140 differ from optical or capacitive plethysmometers?
It relies on hydrostatic pressure transduction rather than light absorption or dielectric shift—offering superior linearity and insensitivity to fur density, skin pigmentation, or ambient light conditions.
Can the same cuvette be reused across animals?
Yes—cuvettes are autoclavable and chemically inert; full decontamination between subjects is required per IACUC-approved SOPs.
Is calibration traceable to NIST standards?
The system is factory-calibrated using certified volumetric standards; users perform daily zero-point verification with dry cuvettes and periodic full-range validation using precision syringes (supplied as optional accessory kit).
Does the software support statistical analysis?
No—data export is designed for downstream processing in GraphPad Prism, R, SAS, or Python-based analytical pipelines compliant with ICH E9 guidelines.
What maintenance is required?
Annual recalibration by Ugo Basile–authorized service centers is recommended; routine cleaning with 70% ethanol and inspection of O-ring integrity suffice for daily operation.