The refractive indices, water content, and volume of wet-spun films of Na-hyaluronate have been measured as a function of relative humidity (rh). These data are used with the Lorentz-Lorenz formula to determine the optical polarizabilities of Na-hyaluronate parallel and perpendicular to the helical axis. The analysis reveals a drop in the optical polarizabilities of approximately 20% between 80 and 88% rh, indicating a phase transition.

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Raman spectroscopy was used to study the low-frequency (⩽200 cm(-1)) vibrations in crystalline samples of six naturally occurring nucleosides: deoxythymidine (dT), deoxycytidine (dC), deoxyadenosine (dA), uridine (rU), cytidine (rC), and adenosine (rA). Such low-frequency vibrations are important for biological processes in which the conformation of a nucleic acid molecule changes. These experiments also provide a test for the low-frequency vibrational modes of dT, dC, and dA predicted by Shishkin et al.