Journal of Applied Crystallography

Volume 39, Part 6 (December 2006)

research papers

J. Appl. Cryst. (2006). 39, 791-796 [ doi:10.1107/S0021889806035163 ]

Scattering from laterally heterogeneous vesicles. I. Model-independent analysis

J. Pencer, V. N. P. Anghel, N. Kucerka and J. Katsaras

Abstract: This is the first of a series of papers considering the scattering from laterally heterogeneous vesicles. Here, it is shown that contrast variation studies on unilamellar vesicles can be analyzed in a model-independent manner to detect lateral segregation in model membranes. In particular, it is demonstrated that the Porod invariant, Q = $\textstyle\int q^{2}I (q )\,{\rm d}q$ , is related to the scattering length density contrast between compositionally distinct regions in a heterogeneous membrane. The formation of domains and the concomitant identification of phase boundaries as a function of either membrane composition or temperature can therefore be detected in the changes taking place in Q.

Keywords: vesicle scattering; contrast variation; membranes.