University of Dundee

Tissue Imaging Facility

Novel regimes; developing technology to probe tissue samples and embryos.

Multiphoton microscopy is an established and proven imaging tool that can provide high-resolution images of flouroscently-tagged proteins or structure in fixed of living specimens. It exploits the inherent confocality and the ability of the infrared multi-photon laser to achieve deep penetration, which is key for imaging thick tissue specimens or whole animals.

This technique allows greater insight into cellular processes in their native environment.  Less well-characterised techniques include Second Harmonic Generation (SHG), a nonlinear light-matter interaction mechanism, which allows imaging of anisotropic biological features with inherent hyperpolarisability without the need for any bio-markers, and Third Harmonic Generation, which enables imaging of interfaces within the imaging focal volume.

The combination of fluorescence imaging by Multiphoton microscopy in conjunction with Second Harmonic Imaging is critical in supporting the research goals of scientists in the University who study dynamic processes in tissue and embryos.

Technologies

  • Advanced multichannel Leica SP8 confocal microscope, which is equipped with an acousto-optical beam splitter (AOBS). This inverted microscope is equipped with a range of excitation wavelengths in the visible regime.
  • The Leica TCS SP8 multiphoton system (upright system with the InSight DeepSee Laser with dual wavelength options enabling simultaneous imaging in the infra red) This allows excitation of a broad range of fluorophores during deep tissue imaging.

The microscope is equipped with 2 detectors in the forward direction and two detectors in the backward direction, an ideal geometry to efficiently collect harmonic signals from the specimen.

People

Wellcome Trust funding supported the purchase of two laser scanning systems and a Scientific Officer in Tissue Imaging, Dr Paul Appleton. The Tissue Imaging Facility was set up in 2014 and is embedded in the Division of Cell and Developmental Biology.