Fluid domain patterns in free-standing membranes captured on a solid support.

T. BHATIA; P. HUSEN; J.H. IPSEN; LUIS A. BAGATOLLI; A.C. SIMONSEN

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 1838 p. 2503 - 2503

0005-2736

e devise a methodology to fixate and image dynamic fluid domain patterns of giant unilamellar vesicles (GUVs) at sub-optical length scales. Individual GUVs are rapidly transferred to a solid support forming planar bilayer patches. These are taken to represent a fixated state of the free standing membrane, where lateral domain structures are kinetically trapped. High-resolution images of domain patterns in the liquid-ordered (lo) and liquid-disordered (ld) co-existence region in the phase-diagram of ternary lipid mixtures are revealed by atomic force microscopy (AFM) scans of the patches. Macroscopic phase separation as known from fluorescence images is found, but with superimposed fluctuations in the form of nanoscale domains of the lo and ld phases. The size of the fluctuating domains increases as the composition approaches the critical point, but with the enhanced spatial resolution, such fluctuations are detected even deep in the coexistence region. Agreement between the area-fract