Photographs of bilayer lipid membranes

 

Formation process is the first stage of any experiment on bilayer lipid membranes. Quality of obtained membranes decides about furteher results. This page presents several photographs made in transmitted light. The pictures show that not all obtained membranes are useful for experiments. The bilayer is always surrounded by the Plateau-Gibbs border consisted of formation solution (lipids dissolved in organic solvent, usually n-alcane). Membranes with smaller border (higher bilayer area) are more stable and phenomena in the border have lower influence on observed results. On end of the table are shown membranes with potential applied to the membrane. This external potential changes area and thickness of the bilayer. The electrocompression phenomenon and changes of interfacial tension cause these changes. 100 mV applied to the shown membrane caused decrease of bilayer thickness from 5.8 nm to 5.5 nm and increase of area at 4.9 %.
 
Photograph of the lenght standard placed in the hole where bilayer lipid membranes are formed. This reference makes possible area measurement of a bilayer part of the membranes. It is necessary for calculation of specific capacitance of the membranes. This hole has diameter about 1 mm.
An example of membrane made of phoshatidylcholine dissolved in n-octane, electrolyte 0.1M KCl. A bilayer is present only in a middle part of the membrane. Border of the membrane contains bubbles of gas. This membrane is unuseful for further experiments.
Membrane made of phosphatidylcholine dissolved in n-decane, electrolyte 0.1M KCl. The bilayer occupies small part of the hole, the Plateau-Gibbs border is large. This membrane is little useful for further experiments.
Membrane made of phosphatidylcholine dissolved in n-decane, electrolyte 0.1M KCl, 10-5M chlorpromazine. The bilayer contains inclusions of the forming solutions in a form of islands. This membrane is little useful for experiments.
Membrane made of phosphatidylcholine dissolved in n-decane, electrolyte 0.1M KCl. This membrane has bilayer of large area. This membrane is stable and useful for any experiments.
Membrane made of phosphatidylcholine dissolved in n-decane, electrolyte 0.1M KCl. This membrane has bilayer of large area. This membrane is stable and useful for any experiments.
Membrane made of phosphatidylcholine dissolved in n-decane, electrolyte 0.1M KCl. This membrane has bilayer of large area. This membrane is stable and useful for any experiments.
Membrane made of phosphatidylcholine dissolved in n-decane, electrolyte 0.1M KCl. This membrane has bilayer of large area. This membrane is stable and useful for any experiments.
Membrane made of asolectin dissolved in n-decane, 20 mg/ml, electrolyte 0.1M KCl, 10mM HEPES, pH 7.0. Polarization potential equal to 0.
Previous membrane, polarization potential 60 mV.
Previous membrane, polarization potential 100 mV.
Previous membrane, polarization potential 140 mV.