Volume 606 of the series Methods in Molecular Biology™ pp 247-269


Studying Lipid Organization in Biological Membranes Using Liposomes and EPR Spin Labeling

  • Witold K. SubczynskiAffiliated withDepartment of Biophysics, Medical College of Wisconsin Email author 
  • , Marija RaguzAffiliated withDepartment of Biophysics, Medical College of Wisconsin
  • , Justyna WidomskaAffiliated withDepartment of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University

* Final gross prices may vary according to local VAT.

Get Access


Electron paramagnetic resonance (EPR) spin-labeling methods provide a unique opportunity to determine the lateral organization of lipid bilayer membranes by discrimination of coexisting membrane domains or coexisting membrane phases. In some cases, coexisting membrane domains can be characterized without the need for their physical separation by profiles of alkyl chain order, fluidity, hydrophobicity, and oxygen diffusion-concentration product in situ. This chapter briefly explains how EPR spin-labeling methods can be used to obtain the above-mentioned profiles across lipid bilayer membranes (liposomes). These procedures will be illustrated by EPR measurements performed on multilamellar liposomes made of lipid extracts from cortical and nuclear fractions of the fiber cell plasma membrane of a cow-eye lens. To better elucidate the major factors that determine membrane properties, results for eye lens lipid membranes and simple model membranes that resemble the basic lipid composition of biological membranes will be compared.

Key words

Liposomes Lipid bilayer Membrane domain Cholesterol Lens lipid Hydrophobic barrier Fluidity Order Oxygen permeation Spin label EPR