title: Fluorescence lifetime optical projection tomography.
abstract: We describe a quantitative fluorescence projection tomography technique which measures the 3-D fluorescence lifetime distribution in optically cleared specimens up 1 cm in diameter. This is achieved by acquiring a series of wide-field time-gated images at different relative time delays with respect to a train of excitation pulses, at a number of projection angles. For each time delay, the 3-D time-gated intensity distribution is reconstructed using a filtered back projection algorithm and the fluorescence lifetime subsequently determined for each reconstructed horizontal plane by iterative fitting to a mono-exponential decay. Due to its inherently ratiometric nature, fluorescence lifetime is robust against intensity based artefacts as well as producing a quantitative measure of the fluorescence signal. We present a 3-D fluorescence lifetime reconstruction of a mouse embryo labelled with an alexa-488 conjugated antibody targeted to the neurofilament, which clearly differentiates between the extrinsic label and the autofluorescence, particularly from the heart and dorsal aorta.
authors.affiliation: Department of Physics, Imperial College London, Prince Consort Road, South Kensington, London, SW7 2BW, UK. james.mcginty@imperial.ac.uk
authors.forename: James
authors.initials: J
authors.lastname: McGinty
authors.forename: Khadija B
authors.initials: KB
authors.lastname: Tahir
authors.forename: Romain
authors.initials: R
authors.lastname: Laine
authors.forename: Clifford B
authors.initials: CB
authors.lastname: Talbot
authors.forename: Christopher
authors.initials: C
authors.lastname: Dunsby
authors.forename: Mark A A
authors.initials: MA
authors.lastname: Neil
authors.forename: Laura
authors.initials: L
authors.lastname: Quintana
authors.forename: James
authors.initials: J
authors.lastname: Swoger
authors.forename: James
authors.initials: J
authors.lastname: Sharpe
authors.forename: Paul M W
authors.initials: PM
authors.lastname: French