Within the EuroBioImaging work package 7 on Advanced Light Microscopy, the Photonics Group at Imperial College London is a Proof of Concept site for Functional imaging.
We develop and apply advanced fluorescence imaging instrumentation with a particular emphasis on fluorescence lifetime imaging (FLIM) applied to FRET readouts for cell biology and label-free contrast in biological tissue. Our fluorescence imaging and FLIM instrumentation ranges from confocal and multiphoton microscopes to automated FLIM multiwell plate readers, FLIM confocal endomicroscopes and FLIM optical projection tomography and diffuse tomography systems.
For the EuroBioImaging Proof of Concept studies, we are particularly aiming to share our expertise in the following areas:
Automated FLIM multiwell plate readers for High Content Analysis, particularly for FLIM FRET studies of protein-protein interactions. Descriptions of this instrumentation can be found in the Journal of Biophotonics (Talbot et al, 2008) and ChemPhysChem (Kumar et al, 2011, open access). Our FLIM multwell plate reader can be configured to provide unsupervised FLIM of fixed or live cells in 96 well plates with a typical data acqusition time of 10 seconds per well or less than 15 minutes per well plate. It operates in wide field imaging mode or provides optical sectioned FLIM images using a Nipkow disc (Yokogawa CSU-X) unit. FLIM is implemented using a gated optical imaging intensifier (Kentech Instruments Ltd HRI). Tunable excitation from the ultraviolet to near infrared is provided by a fibre laser-pumped supercontinuum source (Fianium Ltd) or a mode-locked Ti:Sapphire laser (Coherent MIRA or Spectra Physics MaiTai). If necessary, we can configure our multiwell plate readers for interleaved exciation of multiple fluorophores, e.g. to utilise multiplexed FRET readouts of cell signalling events.
Optical Projection Tomography (OPT) with FLIM. We have developed a FLIM OPT platform that can provide 3-D absorption and fluorescence intensity and lifetime information in samples ranging from ~1-10 mm in scale. We have demonstrated the application of this instrument to fixed and chemically cleared samples such as mouse embryos and tissue samples for histopatholgical analysis and to live organisms such as zebrafish. Descriptions of this instrument can be found in the Journal of Biophotonics (McGinty et al, 2008) and Biomedical Optics Express (McGinty et al, 2011).
We also welcome collaborative projects to take advantage of our multidimensional fluorometer that is able to make measurements on liquid samples in cuvette or on bulk samples via a fibre-optic probe. This instrument, which is described in the Journal of Biophotonics (Manning et al, 2008), is able to resolve fluorescence signals with respect to excitation and emission wavelength, lifetime and polarisation. We have recently adapted this for automated measurements of liquid samples in a 96 well plate format. This instrument is particularly suitable for in vitro studies and homogenous fluorescence based assays, e.g. utilising FLIM FRET. It may be used for preliminary studies before cell-based assays in our FLIM multiwell plate reader.
We also welcome collaborations using any of the other imaging and metrology modalities we are developing in the Photonics Group. Please contact us for further information.