Calcium-induced lateral phase separation in phosphatidic acid/phosphatidylcholine monolayers as revealed by fluorescence microscopy

Biochemistry ◽  
1988 ◽  
Vol 27 (9) ◽  
pp. 3433-3437 ◽  
Author(s):  
Kari K. Eklund ◽  
Jorma Vuorinen ◽  
Jukka Mikkola ◽  
Jorma A. Virtanen ◽  
Paavo K. J. Kinnunen
Keyword(s):  
Phase Separation ◽  
Fluorescence Microscopy ◽  
Phosphatidic Acid ◽  
Lateral Phase Separation

scholarly journals Adhesion-induced lateral phase separation in membranes

2000 ◽  
Vol 3 (3) ◽  
pp. 259-271 ◽  
Author(s):  
S. Komura ◽  
D. Andelman
Keyword(s):  
Phase Separation ◽  
Lateral Phase Separation

scholarly journals Phase separation at the nanoscale quantified by dcFCCS

2020 ◽  
Vol 117 (44) ◽  
pp. 27124-27131
Author(s):  
Sijia Peng ◽  
Weiping Li ◽  
Yirong Yao ◽  
Wenjing Xing ◽  
Pilong Li ◽  
...  
Keyword(s):  
Phase Separation ◽  
Detection Limit ◽  
Fluorescence Microscopy ◽  
Critical Concentration ◽  
Transition Process ◽  
Correlation Spectroscopy ◽  
Cellular Processes ◽  
Conventional Fluorescence Microscopy ◽  
Micrometer Scale ◽  
Liquid Liquid Phase Separation

Liquid–liquid phase separation, driven by multivalent macromolecular interactions, causes formation of membraneless compartments, which are biomolecular condensates containing concentrated macromolecules. These condensates are essential in diverse cellular processes. Formation and dynamics of micrometer-scale phase-separated condensates are examined routinely. However, limited by commonly used methods which cannot capture small-sized free-diffusing condensates, the transition process from miscible individual molecules to micrometer-scale condensates is mostly unknown. Herein, with a dual-color fluorescence cross-correlation spectroscopy (dcFCCS) method, we captured formation of nanoscale condensates beyond the detection limit of conventional fluorescence microscopy. In addition, dcFCCS is able to quantify size and growth rate of condensates as well as molecular stoichiometry and binding affinity of client molecules within condensates. The critical concentration to form nanoscale condensates, identified by our experimental measurements and Monte Carlo simulations, is at least several fold lower than the detection limit of conventional fluorescence microscopy. Our results emphasize that, in addition to micrometer-scale condensates, nanoscale condensates are likely to play important roles in various cellular processes and dcFCCS is a simple and powerful quantitative tool to examine them in detail.

scholarly journals Phase Diagram of Purified CNS Myelin Reveals Continuous Transformation between Expanded and Compacted Lamellar States

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 670
Author(s):  
Julio M. Pusterla ◽  
Emanuel Schneck ◽  
Rafael G. Oliveira
Keyword(s):  
Phase Diagram ◽  
Phase Separation ◽  
Isothermal Transformation ◽  
Phase Behaviour ◽  
Apparent Difference ◽  
X Ray Diffraction ◽  
Lateral Phase Separation ◽  
Diffraction Peaks ◽  
Low Ionic Strength ◽  
Detergent Resistant Membrane

Purified myelin membranes (PMMs) are the starting material for biochemical studies, from individual components up to the isolation of detergent-resistant membrane (DRM) fractions or detergent-insoluble glycosphingolipid (DIG) fractions, which are commonly believed to resemble physiological lipid rafts. The normal DIG isolation protocol involves the extraction of lipids under moderate cooling. The isolation of PMMs also involves the cooling of myelin as well as exposure to low ionic strength (IS). Here, we addressed the combined influence of cooling and IS on the structure of PMMs. The phase behaviour was investigated by small angle X-ray diffraction. Analysis of the diffraction peaks revealed the lamellar periodicity ( d ), the number of periodically correlated bilayers ( N ), and the relatives fractions of each phase. Departure from physiological conditions induced a phase separation in myelin. The effect of monovalent and divalent ions was also compared at equivalent IS, showing a differential effect, and phase diagrams for both ion types were established—Ca2+ induced the well-known over-compacted phase, but additionally we also found an expanded phase at low IS. Na+ promoted phase separation, and also induced over-compaction at sufficiently high IS. Finally, exploring the whole phase diagram, we found evidence for the direct isothermal transformation from the expanded to the compacted phase, suggesting that both phases could in fact originate from the identical primary lateral phase separation, whereas the apparent difference lies in the inter-bilayer interaction that is modulated by the ionic milieu.

Lateral and Vertical Phase Separation Control of Thin-film Structures for Photovoltaics

2001 ◽  
Vol 665 ◽  
Author(s):  
A. C. Arias ◽  
J. D. MacKenzie ◽  
N. Corcoran ◽  
R. H. Friend
Keyword(s):  
Phase Separation ◽  
Spin Coating ◽  
Solution Viscosity ◽  
Separation Control ◽  
Nanometer Scale ◽  
Length Scale ◽  
Photovoltaic Devices ◽  
Photovoltaic Properties ◽  
Lateral Phase Separation ◽  
Photoluminescence Efficiency

ABSTRACTInvestigations on microscopic and photovoltaic properties of polyfluorene blends are presented here. The length scale of lateral phase separation is manipulated by control of solvent evaporation conditions. Photoluminescence efficiency measurements show that charge transfer is more effective in blends phase separated on the nanometer scale. Vertically segregated structures are obtained by a combination of solution viscosity and spin coating conditions. The external quantum efficiency of photovoltaic devices fabricated with vertically segregated blend is found to be 4 times higher than that of devices made with laterally segregated blends.

Directed phase separation of PFO:PS blends during spin-coating using feedback controlled in situ stroboscopic fluorescence microscopy

2013 ◽  
Vol 1 (11) ◽  
pp. 3587 ◽  
Author(s):  
Daniel T. W. Toolan ◽  
Andrew J. Parnell ◽  
Paul D. Topham ◽  
Jonathan R. Howse
Keyword(s):  
Phase Separation ◽  
Fluorescence Microscopy ◽  
Spin Coating
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