Applied Photophysics Hellma Certified CD Cuvettes for Chirascan and Chirascan-Plus Circular Dichroism Spectrometers
| Brand | Applied Photophysics |
|---|---|
| Origin | United Kingdom |
| Manufacturer Type | Authorized Distributor |
| Origin Category | Imported |
| Model | Hellma |
| Price Range | USD 1,850 – 4,300 |
Overview
Applied Photophysics Hellma Certified CD Cuvettes are precision-engineered optical cells designed exclusively for high-sensitivity circular dichroism (CD) spectroscopy. These cuvettes meet the stringent optical and dimensional tolerances required by state-of-the-art CD instruments—including the Applied Photophysics Chirascan and Chirascan-Plus spectrometers—where accurate measurement of differential absorption of left- and right-circularly polarized light is essential for determining secondary and tertiary structural features of chiral biomolecules (e.g., proteins, peptides, nucleic acids) in solution. Constructed from high-transmission, low-autofluorescence fused quartz (Suprasil® or equivalent), each cuvette undergoes rigorous metrological validation and is supplied with a traceable calibration certificate confirming pathlength accuracy to ±0.5% and surface flatness < λ/10 at 250 nm. The cuvettes operate across the full UV–Vis CD range (170–700 nm), with minimal birefringence and negligible CD background signal—critical for achieving sub-millidegree ellipticity detection limits.
Key Features
- Traceable certification per cuvette: includes measured pathlength, surface parallelism, and spectral transmission profile (190–700 nm)
- Optimized quartz grade: Suprasil-type fused silica with certified UV cutoff < 185 nm and refractive index homogeneity < 1 × 10−6
- Multiple standardized pathlengths: 0.01 mm, 0.1 mm, 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm, 5.0 mm, and 10.0 mm—each selected to match sample concentration and absorbance constraints in accordance with the Beer–Lambert law
- Compatible holder system: Includes precision-machined PTFE or stainless-steel cuvette holders with integrated thermal stabilization ports (for temperature-controlled CD experiments)
- Spacer-compatible design: Interchangeable quartz or CaF2 spacers enable fine-tuning of effective pathlength without mechanical repositioning
- Low-stress mounting geometry: Minimizes strain-induced birefringence during insertion into Chirascan sample compartments
Sample Compatibility & Compliance
These cuvettes support aqueous, organic, and mixed-solvent systems—including aggressive media such as trifluoroethanol (TFE), hexafluoroisopropanol (HFIP), and low-pH buffers—without leaching or etching. All materials comply with ISO 17025-accredited calibration practices, and certificate documentation satisfies GLP and GMP audit requirements for structural biology labs conducting regulatory submissions (e.g., FDA IND filings, EMA quality dossiers). The cuvettes are compatible with standard CD sample handling protocols defined in ASTM E2500-22 (“Standard Guide for Specification, Design, and Verification of Pharmaceutical and Biopharmaceutical Manufacturing Systems”) and align with ICH Q5E guidelines on comparability of higher-order structure.
Software & Data Management
While the cuvettes themselves are passive optical components, their certified pathlength values integrate directly into the Chirascan instrument control software (v5.0+), enabling automated correction of ellipticity (θ) to mean residue ellipticity ([θ]MRW) and molar ellipticity ([θ]M). The software supports audit-trail-enabled data logging per FDA 21 CFR Part 11 requirements when used with validated instrument configurations. Certificate metadata (batch ID, calibration date, pathlength value) can be imported via CSV or embedded QR code scanning to ensure full traceability within laboratory information management systems (LIMS).
Applications
- Secondary structure quantification of proteins (α-helix, β-sheet, random coil) using reference deconvolution algorithms (e.g., CONTIN, SELCON3, CDSSTR)
- Thermal and chemical denaturation studies (melting curves, ΔGunfolding, Tm) under controlled temperature ramping (±0.1 °C stability)
- Binding stoichiometry and conformational change analysis in ligand–protein and protein–nucleic acid interactions
- Chirality assessment of synthetic polymers, metalloproteins, and peptide mimetics
- Quality control of biosimilars and biologics during process development and release testing
FAQ
Are these cuvettes compatible with non-Applied Photophysics CD instruments?
Yes—provided the instrument’s sample compartment accommodates standard Hellma CD cell dimensions (e.g., 12.5 × 12.5 mm footprint) and optical alignment tolerances. However, full pathlength-certified performance is guaranteed only on Chirascan-series platforms due to proprietary beam geometry and polarization modulation synchronization.
Can I reuse the same cuvette for multiple samples?
Yes, provided rigorous cleaning protocols are followed: sequential rinsing with high-purity water, ethanol, and dried under nitrogen; avoid ultrasonication unless validated for your specific pathlength variant. Reuse is not recommended for viscous or aggregating samples without post-use inspection under interferometric microscopy.
What is the typical lead time for certified replacement cuvettes?
Standard pathlengths (1.0 mm, 10.0 mm) ship within 5 business days from UK distribution centers; custom or ultra-short pathlengths (0.01 mm, 0.1 mm) require 3–4 weeks due to specialized polishing and certification cycles.
Do spacer sets include calibration documentation?
Yes—each spacer kit is individually certified for thickness tolerance (±0.5 µm) and surface flatness, with certificates cross-referenced to the parent cuvette batch number.
Is there a warranty covering pathlength drift over time?
Hellma provides a 24-month limited warranty against manufacturing defects in dimensional stability; long-term pathlength integrity is maintained under standard lab conditions (20–25 °C, RH < 50%, no direct UV exposure outside measurement cycles).
