Fluorescence of Supported Phospholipid Bilayers Recorded in a Conventional Horizontal-Beam Spectrofluorometer
- 145 Downloads
Supported phospholipid bilayers are a convenient model of cellular membranes in studies of membrane biophysics and protein-lipid interactions. Traditionally, supported lipid bilayers are formed on a flat surface of a glass slide to be observed through fluorescence microscopes. This paper describes a method to enable fluorescence detection from the supported lipid bilayers using standard horizontal-beam spectrofluorometers instead of the microscopes. In the proposed approach, the supported lipid bilayers are formed on the inner optical surfaces of the standard fluorescence microcell. To enable observation of the bilayer absorbed on the cell wall, the microcell is placed in a standard fluorometer cell holder and specifically oriented to expose the inner cell walls to both excitation and emission channels with a help of the custom cell adaptor. The signal intensity from supported bilayers doped with 1 % (mol) of rhodamine-labeled lipid in the standard 3-mm optical microcell was equivalent to fluorescence of the 70–80 nM reference solution of rhodamine recorded in a commercial microcell adaptor. Because no modifications to the instruments are required in this method, a variety of steady-state and time-domain fluorescence measurements of the supported phospholipid bilayers may be performed with the spectral resolution using standard horizontal-beam spectrofluorometers.
KeywordsSupported lipid bilayers Fluorescence Planar membranes Phospholipids Microcell.
E.L.K. acknowledges COR Summer Faculty Fellowship 2014 from Marquette University.
- 3.Bagatolli LA (2007) Membranes and Fluorescence Microscopy. In: C.D. Geddes (ed.), editor. Reviews in Fluorescence. pp. 33–51.Google Scholar
- 5.Crane JM, Tamm LK (2007) Fluorescence microscopy to study domains in supported lipid bilayers. Methods Membr Lipids pp 481-488Google Scholar
- 12.Kinnunen P, Alakoskela J-M, Laggner P, Nejat D (2003) Phase behavior of liposomes. Methods Enzymol: Acad Press pp 129-147Google Scholar
- 13.Janoff AS (1999) Liposomes: Rational Design: Marcel Dekker.Google Scholar
- 14.Walden P (1994) Liposomes as tools for the reconstitution of biological systems. In: Philippot J.R. SF, editor. Liposomes as tools in basic research and industry. Boca Raton: CRC Press. pp. 71–88.Google Scholar
- 18.Lakowicz JR (2010) Principles of Fluorescence Spectroscopy: Springer. 954 p.Google Scholar