Characterization of Z-DNA by Infrared Spectroscopy.

Infrared spectrum stems from the matter's absorption of light in the infrared (IR) light region. Generally, this infrared light absorption is due to the transition of vibrational and rotational energy levels of the involved molecule. Since different molecules have different structures and vibration modes, infrared spectroscopy can therefore be widely applied to analyze the chemical compositions and structures of molecules. Here we describe the method of application of infrared spectroscopy in the investigation of Z-DNA in cells, as infrared spectroscopy can distinguish DNA secondary structures sensitively and the band at 930 cm is specifically attributed to the Z-form DNA. Based on the curve fitting, the relative content of Z-DNA in the cells may be evaluated.