The Jasco J-810 Spectropolarimeter (163-900 nm) is a hybrid instrument consisting of a variable wavelength polarimeter and absorption spectrophotometer. It is designed to allow secondary structure determination by circular dichroism; specifically measuring the left-and right-handed circularly polarized light of optically active molecules. It is equipped with a computer-controlled Peltier device (3-90 °C) and a two-syringe titrator to assess thermal/chemical stabilities of proteins/ polypeptides or to monitor ligand binding and is controlled by Jasco’s Spectra Manager software.