Fluorescence imaging of cholesterol and temperature dependent cell membrane dynamics

Petra Weber; Michael Wagner; Wolfgang S. L. Strauss; Herbert Schneckenburger

doi:10.1117/12.728136

13 July 2007 Fluorescence imaging of cholesterol and temperature dependent cell membrane dynamics

Petra Weber, Michael Wagner, Wolfgang S. L. Strauss, Herbert Schneckenburger

Proceedings Volume 6633, Biophotonics 2007: Optics in Life Science; 663305 (2007) https://doi.org/10.1117/12.728136
Event: European Conferences on Biomedical Optics, 2007, Munich, Germany

Abstract

Cholesterol content is an important factor for membrane dynamics of living cells. With well defined protocols of depletion and enrichment the impact of cholesterol on membrane dynamics was examined by fluorescence microscopy. In addition, the intracellular cholesterol content was determined with biochemical methods. Changes of cholesterol amounts in cell membranes have previously been related to specific disease and may have some influence on the uptake of pharmaceutical agents. A combination of conventional and total internal reflection fluorescence microscopy was applied to the fluorescence marker laurdan, a polarity-sensitive probe, whose electronic excitation energy is different in polar and non-polar environment. Once incorporated into cell membranes, the fluorescence of laurdan shows a spectral shift towards longer wavelength when its molecules get into contact with adjacent water molecules, e.g. when a phase transition from the tightly packed gel phase to the liquid crystalline phase of membrane lipids occurs. The generalized polarization (GP, characterizing this spectral shift) as well as the fluorescence lifetime (τ) of laurdan revealed to be appropriate measures for membrane stiffness and fluidity. GP generally decreased with increasing temperature and was always higher for the plasma membrane than for intracellular membranes. Enrichment of cholesterol caused a pronounced increase, whereas depletion of cholesterol caused a decrease of GP. In addition, pronounced changes of the fluorescence lifetime pattern occurred in the subnanosecond range. GP, and τ were determined as integral values of single cells or small cell collectives and were also displayed as microscopic images.

Citation Download Citation

Petra Weber, Michael Wagner, Wolfgang S. L. Strauss, and Herbert Schneckenburger "Fluorescence imaging of cholesterol and temperature dependent cell membrane dynamics", Proc. SPIE 6633, Biophotonics 2007: Optics in Life Science, 663305 (13 July 2007); https://doi.org/10.1117/12.728136

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available