Related Experiment Video
Updated: Jul 20, 2026

Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy
Published on: October 24, 2017
X-ray diffraction studies of lipid phase transitions in cholesterol-rich membranes at sub-zero temperatures
1Department of Biochemistry, University of Birmingham, U.K.
Abstract:
In X-ray diffraction studies of hydrated (greater than 60%) cholesterol/dioleoylphosphatidylcholine mixtures the lipid packing band showed an abrupt transition from liquid crystal-type to gel-type position and definition at a temperature which decreased progressively to almost -50 degrees C as the proportion of cholesterol was increased to a saturation level of about 50 mol%. Plots of transition temperature against composition (mol% cholesterol) and of peak position against composition provided evidence of a significant change in phospholipid configuration at about 20 mol% cholesterol. However, the data overall suggested a uniform dispersion of the cholesterol molecules in the phospholipid bilayer at all concentrations up to the saturation point. Parallel studies of hydrated lipid extract of erythrocyte membranes and of several cholesterol-rich membrane preparations showed a similar overall change from liquid crystal-type packing at +20 degrees C to a gel-type packing at -30 degrees C to -40 degrees C but without displaying a defined transition temperature.
More Related Videos
Related Concept Videos
Phase Transitions: Melting and Freezing
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
Determination of Crystal Structures

