The result is that the plane of the light wave is rotated and that the addition of the E R and E L vectors results in a vector that traces out an ellipse and the light is said to be elliptically polarized. When asymmetric molecules interact with light, they may absorb right and left handed circularly polarized light to different extents (hence the term circular dichroism) and also have different indices of refraction for the two waves. The waves are 90 degrees out of phase with each other and can be separated using a variety of prisms or electronic devices which utilize Pockel's effect 1.
The two circularly polarized waves have physical existence. When viewed from the front, the sinusoidal wave can be visualized as the resultant of two vectors of equal length, which trace out circles, one which rotates clockwise (E R) and the other which rotates counterclockwise (E L). If the light is polarized by passing through suitable prisms or filters its electric field, E, will oscillate sinusoidally in a single plane. A beam of light has time dependent electric and magnetic fields associated with it. Briefly, circular dichroism is defined as the unequal absorption of left-handed and right-handed circularly polarized light. Circular dichroism (CD) is an excellent method for rapidly evaluating the secondary structure, folding and binding properties of proteins. It incorporates two monochromators, one of emission and one of excitation, both with variable slit, that allow to select the excitation wavelength and the fluorescence bandwidth suitable in each case. Its range 250 to 850nm can be extended to 1,100 with the addition of a specific PMT detector and can be added most models compatible accessories J-1700 and J-1500.The rapid characterization of new proteins is of great importance for the fields of proteomics and structural genomics. The model CPL-300 allows the measurement of circularly polarized luminescence (CPL), measures the difference in intensity of polarized fluorescence right and left, complementing the information of chiral compounds obtained through absorption techniques such as CD and VCD. The J-1700’s innovative optical system enables measurement of a CD spectrum in the near IR region up to 2,500 nm using an exclusive triple detection system. The J-1700 model is ideal for the structural analysis of organometallic complexes and colored proteins, as well as acquisition of magnetic CD spectra of transition metals and measurements of the first and second overtones of vibrational transitions. The range up to 2500nm allows you to link your spectra to those obtained by the FVS-6000 VCD Vibrational Circular Dicroism. The J-1500 model allows the measurement of a CD spectrum in the UV region of vacuum at 163 nm. The UV vacuum region below 200 nm is of critical importance for biomolecules, in particular in the secondary structure estimation protein. As standard, its PMT detector allows to mediate up to 900nm, however the addition of an optional second InGaAs detector allows measurements with the highest sensitivity up to 1,600nm. Combined with a high scanning speed of 10,000nm / min, it is possible to measure samples quickly with a minimum exposure time of biological samples, which minimizes the risk of sample degradation.
Jasco spectra manager circular dichroism series#
The new J-1100 Series is a compact system that meets most of the demands for routine biomolecule analysis.
For more than 50 years JASCO has been a pioneer in the implementation of Circular Dichroism. The new J-1000 series is the result of the application of the most advanced technology to meet the demands of our customers. These three new models can be adapted to meet any requirement and can be expanded depending on the evolution of your needs.