RADIATION-DAMAGE IN TRIPALMITIN LAYERS STUDIED BY MEANS OF INFRARED SPECTROSCOPY AND ELECTRON-MICROSCOPY

Structural deteriorations in biomembranes, as inevitably induced while structural information is gathered by electron optical methods, were evaluated by infrared spectroscopy. Tripalmitin model membranes were irradiated with 100 keV-electrons by EM. The intensity decay of group vibrations over the dose reveals the sequence of damage in the polar and nonpolar part of the molecule. The C.sbd.C backbone, being the most important structural features, shows a significant latency effect up to 0.6 e-/.ANG.2 and is completely disordered by 3 e-/.ANG.2, corresponding to about 3 inelastic processes/molecule.