Chirascan

Applied Photophysics Спектрометр кругового дихроизма AppliedPhotophysics Chirascan купить в Техноинфо

Suitable for studying chiral molecules of all types and sizes, this Chirascan CD spectrometer has featured in thousands of publications since its introduction in 2005. Often used to analyze biomolecules, Chirascan data contributes to a deeper understanding of biomolecular characteristics, mechanisms and interactions.



More than α-helix and β sheet - determine structural and thermodynamic properties

Determine structural and thermodynamic properties

  • Gain insight and detect changes in secondary and tertiary structure
  • Determine response to thermal or chemical changes
  • Study folding and unfolding mechanisms

Achieve highest sensitivity and accuracy

Generate highest quality data

Optimize sample concentration and absorbance

Expand capabilities with dedicated Chirascan accessories

Chirascan systems are delivered ready to run, including flow cells and/or cuvettes selected for the most common analytical conditions.

Deepen understanding of biomolecular characteristics, mechanisms and interactions

Detect minor differences under native or stressed conditions

Characterize protein stability

  • Determine response to thermal or chemical changes
  • Determine structural and thermodynamic properties
  • Study folding and unfolding mechanisms

READY TO RUN – GENERATE HIGHEST QUALITY DATA

Chirascan systems are supplied with features and accessories required for acquisition of high quality CD data – from built-in temperature control during analysis to cuvettes for the most common analytical conditions.* A basic training program follows installation to familiarize users new to Chirascan.

AVALANCHE PHOTODIODE DETECTOR (CHIRASCAN V100)

  • Highest sensitivity (high signal: noise)

PHOTOMULTIPLIER DETECTOR (CHIRASCAN)

PHOTOELASTIC MODULATOR

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

MONOCHROMATOR

  • Produces horizontally, linearly polarized monochromatic light
  • Two polarizing prisms maximize light throughput

AIR-COOLED XENON LAMP

  • Software-controlled
  • Up-time recorded

ACTIVE NITROGEN MANAGEMENT SYSTEM

  • Regulates purge gas consumption
  • Software-controlled

TEMPERATURE-CONTROLLED SAMPLE CHAMBER

  • Consistent analytical conditions
  • Continuous temperature ramps
  • Temperature measured directly in sample

OPTICS-BASED, MULTIWAVELENGTH CALIBRATION

  • For CD accuracy (Chirascan V100)

CUVETTES AND HOLDER

  • Selected for far- and near-UV CD analysis of biomolecules

WATER CIRCULATOR

  • Dissipates heat from sample chamber Peltier

CHIRASCAN CONTROL

  • Easily define run parameters and store routine protocols
  • Saves time with scheduled start-up/shutdown of lamp and N2 supply
  • Fail-safe lamp switch-off if N2 flow drops
  • Ensures O2-free conditions with N2 purge

CONTROL AND ANALYSIS SOFTWARE GLOBAL THERMODYNAMIC ANALYSIS

  • Derive melting points and enthalpies from multiwavelength, thermal denaturation experiments

Chirascan accessories:

CCD FLUOROMETER: Monitor changes in fluorescence. Controlled through Chirascan software, the CCD fluorometer generates emission spectra in seconds providing CD, absorbance and fluorescence data in a single experiment.

6-CELL TURRET: Increase capacity and productivity. Controlled through Chirascan software, the 6-cell turret enables analysis of up to six samples or 6 thermal denaturation data sets per run. Precision Peltier temperature control and magnetic stirring provide optimal conditions for thermal denaturation (temperature ramp) experiments.

TITRATOR AND pH PROBE: Monitor concentration- and pH-dependent changes in CD, fluorescence or absorbance. Fully automated and controlled through Chirascan software, this dual syringe titration system systematically varies concentration of solution while maintaining constant volume. The optional pH probe enables measurement of sample pH in situ.

LD COUETTE CELL: Gain insight into conformation and relative orientation of molecules. The LD Couette Cell enables study of macromolecular structures and their interactions e.g. DNA-ligand binding or orientation of membrane proteins. These structures are either intrinsically oriented or can be oriented during an experiment.

STOPPED-FLOW: Characterize fast reactions, complement CD spectra with kinetic information. Using the world-leading design of the stopped flow accessory enables study of reactions in solution and determination of rate constants. Changes in CD, absorbance, fluorescence or fluorescence polarization can be monitored as a function of time.

INTEGRATING SPHERE AND SOLID SAMPLE HOLDER: See changes in chirality of solid state samples. The integrating sphere contains a large reflecting area to ensure high signal:noise when collecting CD data from highly scattering samples such as solids and powders. A wheel in the solid sample holder enables rotation of transparent samples such as KBr discs to eliminate birefringence effects.

ALSO AVAILABLE

A FLUORESCENCE ANISOTROPY DETECTOR to characterize ligand binding events.

An OPTICAL ROTATORY DISPERSION accessory to characterize chiral molecules at high concentration, where absorption bands are obscured by solvent or buffer salt absorption, or when measuring at wavelengths where a chiral molecule does not necessarily absorb light.

A MAGNETIC CD accessory for study of molecules such as metalloproteins.

A NEAR IR EXTENSION KIT to expand scanning range of a Chirascan V100 to 1700 nm.

Performance characteristics
Spectral information: CD, absorbance as standard, Fluorescence and other detection modes available

Isothermal analysis, typical measuring time: Full spectrum < 2 min

Isothermal analysis, typical sample consumption:

  • Secondary structure (far-UV), 0.5 mm pathlength, cell width 9 mm: mAb 0.06 mg
  • Tertiary structure (near-UV), 10 mm pathlength, cell width 10 mm: mAb 2.8 mg
  • Tertiary structure (near-UV), 10 mm pathlength, cell width 4 mm: mAb 0.5 mg

Thermal denaturation (thermal ramping): Full spectrum per 1°C, continuous ramp rate 1°C/min

Technical specifications: Chirascan

Light source: 150W air-cooled Xenon arc lamp

Monochromator: Two polarizing prisms to maximize light throughput

Detection: Photomultiplier

Wavelength range (Note: using quartz prisms within monochromator limit measurements to wavelengths > 163 nm): 163 nm to 900 nm (Typical wavelength range for biomolecule analysis 180 nm to 350 nm)

Wavelength resolution: ±0.1 nm

CD calibration: Chemical-based, single point

Measurement error on absolute absorbance: < 0.1 AU

Bandwidth:

  • 160 nm: up to 2 nm
  • 180 nm: up to 4 nm
  • 200 nm: up to 7.5 nm
  • 240 nm: up to 16 nm

Bandwidth precision: ±0.1 nm at 267 nm

Stray light: < 3 ppm at 200 nm

Typical Root Mean Square (RMS) noise values, no sample in place, 1 nm bandwidth, 2 s digital integration time – no smoothing, no rolling average:

  • 0.045 mdeg at 185 nm
  • 0.045 mdeg at 250 nm
  • 0.055 mdeg at 500 nm

Baseline stability (16 h drift test): < 0.5 mdeg

Sample temperature during analysis, coolant at 15°C or above:

  • Hardware tolerance: -20°C to +105°C
  • Typical range for biomolecule analysis: 4°C to 95°C

Data handling and storage

PC operating system: Microsoft® Windows® 7 Professional, 64 bit

Data storage and export: Storage in proprietary format, exportable as .csv

Compliance

Physical and environmental specifications

Instrument weight and dimensions (WxDxH): 60 kg, 150 x 55 x 60 cm

Operating conditions:

  • temperature 20 to 25°C controlled to within 1.5°C
  • humidity 20 to 80 % non-condensing

Nitrogen requirement (flow rate, pressure, purity): 5 L per min, > 4 bar, > 99.998%

Chirascan systems are delivered ready to run, including flow cells and/or cuvettes selected for the most common analytical conditions.