SPIEDL Logo

GENERAL INFORMATION

You are not logged in Logged Out Log In

Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations

J. Biomed. Opt. 17, 016007 (Feb 06, 2012); http://dx.doi.org/10.1117/1.JBO.17.1.016007

Neveen A. Hosny, David A. Lee, and Martin M. Knight

University of London, School of Engineering and Materials Science, Queen Mary, London, United Kingdom, E1 4NS

University of London, School of Biological and Chemical Science, Queen Mary, London, United Kingdom, E1 4NS

Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2’-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)3]2+, was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)3]2+ characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

© 2012 Society of Photo-Optical Instrumentation Engineers

History
Received Aug 24, 2011
Accepted Nov 14, 2011
Revised Oct 21, 2011
Published online Feb 06, 2012
Citation
Neveen A. Hosny, David A. Lee and Martin M. Knight, "Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations", J. Biomed. Opt. 17, 016007 (Feb 06, 2012); http://dx.doi.org/10.1117/1.JBO.17.1.016007

DOWNLOAD ARTICLE

LOG IN or SELECT A PURCHASE OPTION:

RELATED CONTENT

More Like This Article


For access to fully linked references, you need to log in.

Close

close