title: In vivo fluorescence lifetime tomography of a FRET probe expressed in mouse.
abstract: Förster resonance energy transfer (FRET) is a powerful biological tool for reading out cell signaling processes. In vivo use of FRET is challenging because of the scattering properties of bulk tissue. By combining diffuse fluorescence tomography with fluorescence lifetime imaging (FLIM), implemented using wide-field time-gated detection of fluorescence excited by ultrashort laser pulses in a tomographic imaging system and applying inverse scattering algorithms, we can reconstruct the three dimensional spatial localization of fluorescence quantum efficiency and lifetime. We demonstrate in vivo spatial mapping of FRET between genetically expressed fluorescent proteins in live mice read out using FLIM. Following transfection by electroporation, mouse hind leg muscles were imaged in vivo and the emission of free donor (eGFP) in the presence of free acceptor (mCherry) could be clearly distinguished from the fluorescence of the donor when directly linked to the acceptor in a tandem (eGFP-mCherry) FRET construct.
authors.forename: James
authors.initials: J
authors.lastname: McGinty
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Stuckey
authors.forename: Vadim Y
authors.initials: VY
authors.lastname: Soloviev
authors.forename: Romain
authors.initials: R
authors.lastname: Laine
authors.forename: Marzena
authors.initials: M
authors.lastname: Wylezinska-Arridge
authors.forename: Dominic J
authors.initials: DJ
authors.lastname: Wells
authors.forename: Simon R
authors.initials: SR
authors.lastname: Arridge
authors.forename: Paul M W
authors.initials: PM
authors.lastname: French
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Hajnal
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sardini