THz characterization of DNA

We have investigated DNA with pulsed THz radiation using various types of DNA. The refractive index depends strongly on the relative humidity and correlates well with the number of water molecules per nucleotide plus a background not depending on water. Low-temperature (10 K) spectra suggest that DNA absorption spectra should have a peak density narrower than 6 GHz in the range from 0.15 to 1.6 THz.