MicroCal PEAQ-DSC Manual

The MicroCal PEAQ-DSC manual instrument provides easy-to-use, highly sensitive microcalorimetry that helps to reduce the time and cost associated with comparability analysis and stability testing. The MicroCal PEAQ-DSC is a manual instrument with a cleaning device, which can be upgraded to an automated version upon request.

The data generated by the MicroCal PEAQ-DSC provides important guidance for biopharmaceutical development in (pre)formulation development, protein engineering, manufacturing change control, process development, and biocomparability and biosimilarity studies.

The integrated software simplifies workflows, enables non-subjective data analysis, performance qualification and compliance with 21 CFR Part 11 and Annex 11 regulations, resulting in high integrity data and stimulating productivity in biopharmaceutical research.

Differential Scanning Calorimetry (DSC) is a powerful analytical tool that characterizes the thermal stability of proteins and other biomolecules. The method measures the temperature (T_M) and enthalpy (ΔH) of thermally-induced structural transitions of molecules in solution.

This information provides important insights into factors that stabilize or destabilize proteins, micellar complexes, nucleic acids, and other macromolecular systems.

The data is used to estimate the shelf-life of biomolecular products including biopharmaceuticals, to develop purification strategies, to facilitate biosimilar and batch-to-batch versus innovator molecule comparisons, to characterize and assess protein constructs, and to rank the affinities of ligands to their protein targets in small molecule drug discovery programs.

The high-sensitivity MicroCal PEAQ-DSC system features automated data analysis to support the production of high integrity thermal stability data and deliver compliance with regulatory requirements, while also allowing easy integration into exisiting data handling and transfer systems.

Unattended operation of the instrument after sample loading frees up operator time. This comprehensive system does not require extra reagents, accessories, or consumables.

Key Features

The key features of the MicroCal PEAQ-DSC Manual System are as follows:

Manual system with cleaning device and pipette

Gold standard stability-indicating method requiring minimum assay development

Direct and label-free measurement of biomolecular native-state stability in solution

Measurement of very tight binding constants, up to 10²⁰M^-1

Powerful MicroCal PEAQ-DSC software reduces usual data analysis time and includes:

PEAQ-Compare: For the quantitative comparison of DSC traces for comparability studies, ideal for batch-to-batch and biosimilarity studies

PEAQ-Compliance: The system is available with Malvern Panalytical Access Controller (MAC) to limit access to user-defined SOPs and data analysis features. Data can be displayed using the Report Generator with user details and the ability to sign using electronic signatures to facilitate the integration of the workflow into your company’s quality system and aid compliance with 21 CFR Part 11 and Annex 11 regulations. This is available as an optional accessory

PEAQ-Smart (including PEAQ-Finder): For SOP-based operation and data analysis. Provides new algorithms to detect even subtle peaks and shoulders, facilitating the automatic, non-subjective identification of multiple transitions, such as those seen in multi-domain proteins

PEAQ-Performance: Automatically detects and validates system readiness for optimal performance

Network-ready: email updates sent during the analysis to keep users informed of assay progress

The MicroCal PEAQ-DSC Automated, with an autosampler, is also available.

How It Works

Functional structures produced by proteins and other macromolecules frequently undergo temperature-induced conformational alterations, such as unfolding. These alterations cause the absorption of heat due to the redistribution of non-covalent bonds within the molecule. Differential Scanning Calorimeters measure this heat uptake very precisely.

The MicroCal PEAQ-DSC system’s thermal core contains a reference cell (containing a matched buffer solution) and a sample cell (containing the sample of interest). Both cells are placed within an insulating jacket. They are constantly maintained at the same temperature, and while a measurement is performed, they are heated at a constant scan rate.

When the molecule inside the sample cell unfolds, heat is absorbed, forming a temperature difference (ΔT) between the reference cell and the sample cell. This results in a thermal gradient across the Peltier units, forming a proportional voltage, which is then converted to power to create a feedback loop to the Peltier units, in order to return ΔT to zero.

As protein unfolding is an endothermic occurrence, it is seen as a positive displacement in the thermogram. This protein ‘melting’ transition’s midpoint is the T_M, and the area under the curve is the enthalpy (ΔH) of the unfolding process (refer figure below).

Specifications

General

Technology: Differential Scanning Calorimetry

Measurement type: Temperature midpoint (T_M); Enthalpy (ΔH); Heat capacity change (ΔC_p)

Cell

Cell: Capillary

Cell material: Tantalum

Cell volume: 130 µL

Sample

Sample volume: 250 µL (manual filling)

Typical sample concentration: 0.01 mg/mL – 10 mg/mL¹

Sample throughput: ≤6 samples analyzed/8h

System

Noise: 0.05 µCal/°C ²

Baseline repeatability: 1 µCal/°C ²

Response time: 5s ²

Repeatability: <0.2 µCal/°C ³

Reproducibility: <0.08 °C St. Dev. T_M and <2% RSD on ΔH ⁴

System reproducibility: <0.1°C St. Dev. T_M and <5% RSD on ΔH ⁴

Multiple feedback modes: Yes (high gain, passive, and low gain)

Temperature range: 2 °C to 130 °C ^2,5

Maximum scan rate: 240 °C/h

Reverse scanning: Yes

Pressure perturbation calorimetry (PPC): N/A - manual cleaning device with guided workflows

Cleaning solvents: Water and detergent (Contrad 90) used as standard

Software

21 CFR part 11: Yes, with PEAQ-Compliance software option

Network ready: Yes, with email alert capability

Software

21 CFR part 11: Yes, with PEAQ-Compliance software option

Network ready: Yes, with email alert capability

Operating Environment

Operating temperature (°C): +10 °C to +28 °C

Storage temperature: -20 °C to +50 °C

Humidity: 10% to 70%, non-condensing (10% to 90% for storage)

Ingress Protection (IP) rating: IP21Power:100-240 V A/C, 50/60 Hz, 70 W (cell), PC as supplied

Certification: CE (EN61010-1), EMC (EN61326-2-1, EN61326-1, ICES, FCC, VCCI), ISO9001:2008

Weight and dimensions

Dimensions (W, D, H): 20 cm x 44 cm x 19 cm

Weight: 8.2 kg

Notes

¹ Sample dependent² Typical results for ribonuclease (RNase) in 50 mM KAc buffer at pH 5.5, at 60 °C/h with passive feedback³ Rescans of a stable buffer⁴ Using ribonuclease (RNase)⁵ Range may be extended down to -10 °C upon request