Chirascan
Q100

Product details

Resources Support Contact

Chirascan
Q100

Product details

Resources Support Contact

THE WALK-AWAY CIRCULAR DICHROISM INSTRUMENT FOR REGULATORY ENVIRONMENTS

Chirascan Q100 provides detailed insight into the Higher Order Structure (HOS) characteristics of complex biomolecules.

Reproducible robotics and high performance circular dichroism spectroscopy combine to generate quality data compatible with the most stringent statistical analysis methods. The result: objective, statistically-validated HOS comparisons.

Fully integrated for unattended operation, Chirascan Q100 saves days of operator time, analyzing 48 buffer-sample pairs over 24 hours whereas an experienced operator processes up to 14 samples per day on a manual system.

Performance

Increased sensitivity for superior detection

Avalanche photodiode detector enhances sensitivity
Higher signal:noise ratio than conventional photomultiplier tube detectors
Accurate normalization from simultaneous measurement of absorbance and CD

For being able to identify minor spectral differences due to subtle changes in molecular structure, high sensitivity is key—particularly for tertiary structure assessment by near-UV CD and HOS comparisons, e.g., for forced degradation studies.

Calibration with confidence

Accurate CD values across entire wavelength range
Overcome challenges of chemical calibration
Optics-based, multiwavelength calibration

Conventional chemical calibration methods require considerable skill in preparation. Standards, such as camphor-10-sulfonic acid (CSA), are unstable, photolabile, and hygroscopic. In addition, single-wavelength calibration (290.5 nm) assumes the same linear response at all wavelengths.

The optics-based, multiwavelength calibration method used for Chirascan V100 and Chirascan Q100 systems overcomes these challenges. The correct calibration is applied to every wavelength to yield accurate CD values.

Publications

Features and accessories

Chirascan systems are supplied with the features and accessories required for acquisition of high quality data from ‘day one’.

Molecular sieve, activated charcoal filter

Removes common gas impurities

Active nitrogen management system

Regulates purge gas consumption
Software-controlled

Air-cooled xenon lamp

Software-controlled
Up-time recorded

Monochromator

Produces horizontally, linearly polarized monochromatic light
Dual polarizing prisms maximize light throughput

Photoelastic modulator

Converts horizontally polarized light to circularly polarized light. Alternates between left- and right-handed circular polarized light

Integrated autosampler

Eliminate sample handling errors
Precise liquid handling and reproducibility
Temperature-controlled storage maintains sample integrity

Temperature-controlled sample chamber

Consistent analytical conditions
Continuous temperature ramps (single sample mode)

Water circulator

Dissipates heat from sample chamber and sample storage Peltiers

Avalanche photodiode detector

Highest sensitivity (high signal: noise)

Optics-based, multiwavelength calibration

For CD accuracy at every wavelength

Fixed flow cells

Eliminates errors of cuvette handling
Recognized by Chirascan Control to select run/wash/dry protocols
Choice of pathlength to optimize concentration and absorbance

Cuvettes and holders

Selected for far- and near-UV CD analysis of biomolecules (single sample mode)

HOS Comparison Software

Optimized for Chirascan Q100

Confirming the statistical significance of any detected change in HOS requires a minimum of five sample replicates to enable robust analysis*. HOS comparison software is therefore optimized for analysis of the raw (unsmoothed) data generated on a Chirascan Q100 system to ensure
An ability to detect minor changes in HOS
An autosampler and flow cell combine to increase reproducibility by eliminating variability due to manual handling of samples and cuvettes
An avalanche photodiode detector achieves a sensitivity far greater than a conventional photomultiplier detector
An ability to increase number of replicates without increasing demands on operator time

The software includes comparison methods and statistics associated with several statistical methods. However, we recommend calculating z-scores to quantify the similarity between a single spectrum and the reference dataset for each sample using ‘weighted spectral difference’ Dinh et al.

For more information about quality range tests consult guidance documents from the relevant regulatory agencies. For example: Development of Therapeutic Protein Biosimilars: Comparative Analytical Assessment and Other Quality-Related Considerations – Guidance for Industry, CDER, FDA

*Analyses with three or four replicates can be sufficient for proof of principle studies, but statistical analysis with less than three replicates is not mathematically possible

Note: t-tests are not recommended for HOS comparisons and are absent from the statistical approaches recommended by regulatory agencies at this time.

HOS Comparison software enables calculation of weighted spectral difference scores for reference and sample datasets – converting spectra into numerical data.
These scores are then exported and used to generate a quality range test or equivalence test as recommended by the FDA.