[16] Infrared spectroscopy of DNA

Publisher Summary This chapter presents a general survey of the Fourier-transform infrared (FTIR) spectrum of a nucleic acid, describes the characterization of the different classic families of DNA conformations, and then discusses the way FTIR spectroscopy can be used in the study of DNA recognition, particularly in the case of triple-stranded structures and DNA–drug interactions. Compared to other techniques some of the advantages of infrared spectroscopy in the study of nucleic acids are (1) the possibility of obtaining data from samples under an extremely wide variety of physical states, (2) no limitation introduced by the size of the investigated molecule—that is, it can work well with short oligonucleotides as well as long polynucleotides, DNA fragments obtained by enzymatic or chemical cleavage, or high molecular weight native DNAs, (3) infrared spectroscopy is a nondestructive technique, which requires only small amounts of samples, and (4) it gives vibrational information characteristic of the helical conformations of the nucleic acids.