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J-1700 Circular Dichroism Spectrophotometer

J-1700 Circular Dichroism Spectrophotometer

UV, Visible, and NIR measurements up to 2500 nm for MCD and specialized applications.

The J-1700 was specifically designed for more demanding near-infrared CD applications. In addition to the enhanced far-UV capabilities, researchers probing the chiral activity of molecules in the NIR spectral region now have the ability to obtain data at wavelengths up to 2500 nm

System description

The InGaAs detector has a wavelength range from 900-2500 nm, while the PMT ranges from 163-960 nm. The automatic detector interchange allows researchers to obtain both far-UV and NIR measurements without having to manually switch detectors. The addition of a grating monochromator to the double-prism monochromator setup provides low stray light and high light intensity, generating CD signals with high S/N performance throughout a large spectral range.

NIR-CD applications vary from conformational and chirality studies of metal coordination complexes to tuning chiral properties of nanomaterials. Additionally, Magnetic Circular Dichroism (MCD) can be used in conjunction with NIR-CD to probe a chromophore’s electronic structure as well as to induce chirality in compounds.

  • ● Wavelength range 163-2500 nm
  • ● Low stray light
  • ● Simultaneous Multi-Probe (SMP): CD, LD, fluorescence, UV-visible, absorbance
  • ● Integrated Hg lamp for wavelength calibration
  • ● Three scanning modes: auto, step and continuous
  • ● Highly efficient nitrogen purge system: low volume monochromator designed using a flow simulator

Product Specialist

Mats Grapne Kovalent

Mats Grapne

"More than 30 years experience in the field of HPLC, Spectroscopy and other analytical equipments. Contact me if you have questions or need a quotation"

Instrument performance

Enhanced Vacuum-UV Measurement

The innovative optical system of the J-1500 permits the measurement of a CD spectrum in the vacuum-UV region down to 163 nm. The enhanced light throughput and new digital lock-in technology now allows for a small signal to be detected in a very noisy environment. Additionally, the optimization of the nitrogen purge efficiency helps to reduce the amount of oxygen in the optical bench so it does not bury the sample signal.

These features ensure that CD spectra can be obtained from strongly absorbing and high signal-to-noise (S/N) samples across the spectrum and into the vacuum-UV region. The quality of spectral data obtained, including data obtained at shorter wavelengths, substantially improves the accuracy of protein secondary structure analysis.

α-pinene enantiomers (gas phase) showing excellent performance in the Far-UV region.

CD spectra of Human Serum Albumin (Helix rich), Concanavalin A (β-sheet rich) and Trypsin inhibitor (Random rich) in water with excellent signal to noise to 174 nm.

The same α-pinene sample showing similar superior performance in the vacuum-UV region down to 163 nm.

Exceptional Stray-Light Rejection

The double polarizing prism monochromators of the J-1000 series result in stray light lower than 0.0003%, enabling the instruments to obtain high-quality CD data even under conditions with high absorbances

Rapid Scanning

High sensitivity combined with a 10,000 nm-per-minute maximum scan speed allows the J-1500 to measure samples quickly, increasing productivity in your lab. An additional benefit is the minimal time exposure of biological samples to the high-energy UV light, minimizing the risk of sample degradation. A mechanical shutter can also be programmed to open and close only during actual measurement to further avoid UV exposure.

High Sensitivity and Wide Dynamic Range of PMT Detector

The PMT detectors used in the JASCO system are specially selected for the highest sensitivity and lowest birefringence. The wide dynamic range of the PMT detector ensures that large variations in signal intensity can still be detected, even for highly absorbing samples. The result is superior linearity between concentration and absorbance compared to other types of detectors including solid-state APD and CCD detectors.

The gain on a PMT detector is much larger  than most detectors, and therefore the signal amplification is larger. Under conditions with adequate light intensity, this typically leads to a larger amount of noise and therefore a lower S/N ratio. However, under conditions where there is a small amount of light hitting the detector (i.e. far-UV region), the gain of the PMT allows for good signal amplification at very low noise, increasing the S/N ratio.

Highest S/N Performance

The high S/N (signal-to-noise) performance of the J-1000 series is achieved by a high throughput optical system and low-noise signal processing. RMS Noise < 0.004 mdeg (185 nm) for the J-1500 and J-1700, < 0.03 mdeg (200 nm) for J-1100.

Simultaneous Multi-Probe Measurements

The latest quad-channel lock-in amplifier provides simultaneous acquisition of up to four data channels including CD, HT, DC, absorbance, linear dichroism (LD), fluorescence, fluorescence-detected CD (FDCD), fluorescence-detected LD (FDLD) and fluorescence anisotropy.

Additionally, the lock-in amplifier obtains a signal at a specific resonance frequency while filtering out noise signals at other frequencies, providing spectra with excellent signal-to-noise ratios.

Multi-probe measurement of Lysozyme showing the simultaneous acquisition of CD, Absorbance, Ex Fluorescence and Em Fluorescence during a thermal-ramping experiment.


The only CD instrument designed to explore the structure and stability of biomolecules by providing the maximum signal-to-noise under highly absorbing, low light intensity conditions of the far-UV spectral region.

The J-1000 Series Circular Dichroism spectrophotometers are specifically designed for high sensitivity measurements in the near- and far-UV regions, for scientists that need confidence in the data from characterization studies of biomolecule structure, function and stability under a wide variety of experimental conditions.

Unlike some detectors which only provide good signal-to-noise for low absorbing materials, the J-1000 Series circular dichroism spectrophotometers use high dynamic range detectors to obtain high quality spectra of samples with excellent signal-to-noise, especially for highly absorbing materials found in the far-UV.
  • Advanced Features of the J-1000 Series
    • High optical throughput
    • Double prism monochromator providing low stray light
    • Wide dynamic range PMT detector
    • Highly efficient nitrogen purge system
    • Digital signal processing Simultaneous
    • Multi-Probe: CD, LD, HT, DC, absorbance, fluorescence
  • Unique Benefits and Accessories
    • Compact benchtop design
    • Range of precise temperature control accessories
    • High-throughput automated CD
    • Automated titration and stopped-flow
    • Spectra Manager™ software for control and extensive data analysis
    • Flexible design allows field upgrades for different measurement capabilities as applications and budgets evolve
  • Versatility for a Wide Range of Applications 
    • Protein conformational studies
    • Quantitative analysis of pharmaceuticalsFormulation studies
    • Protein folding studies
    • DNA/RNA interactions
    • Enzyme kinetics
    • Purity testing of optically active substances
    • Natural products chemistry