Evaluation of Instrumental Errors Built in Circular Dichroism Spectrometers

Because of the increased use of circular dichroism (CD) spectroscopy as a routine technique by nonspecialists to determine the conformational/configurational properties of biomolecules, we have decided to present here some criteria to accurately check the ordinate scale calibration of a CD spectrometer particularly in the critical lowwavelength UV region, to understand, and correct, where possible, the potential limitations coming from the hardware. We also analyze some wavelength calibration methods, and some standards for the CD-scale calibration, and we discuss the critical characteristics of current instrumentation affecting measurements. The example of the bovine catalase CD spectrum is considered.