Biophotonics

New advances in imaging techniques now provide the ability to image three-dimensional (3D) structures, measure interactions by multi-colour co-localization, and record dynamic processes in living cells at the nanometer scale.

A number of “super-resolution” fluorescence microscopy techniques have been invented to overcome the diffraction barrier, including techniques that employ nonlinear effects to sharpen the point-spread function of the microscope, such as stimulated emission depletion (STED) microscopy, related methods using other reversible saturable optically linear fluorescence transitions (RESOLFTs), and saturated structured illumination microscopy (SSIM), as well as techniques that are based on the localization of individual fluorescent molecules, such as stochastic optical reconstruction microscopy (STORM), photoactivated localization microscopy (PALM), and fluorescence photoactivation localization microscopy (FPALM). These methods have yielded an order of magnitude improvement in spatial resolution in all three dimensions over conventional light microscopy. The observation of previously unresolved details of cellular structures has demonstrated the great promise of super-resolution fluorescence microscopy in elucidating biological processes at the cellular and molecular scale. Currently, there are only a handful of super-resolution microscopes in the UK, and at present only one system, a SULSA funded OMX microscope (see figure below), exists locally in Scotland. As ever, with this high specificity equipment, there is a tendency for this type of equipment to become obsolete as soon as it is commissioned.  Usually these apparatus can perform only one type of microscopy. Therefore what we propose is that we build the UK’s first truly reconfigurable super-resolution microscope.

         Uniquely, within St Andrews, we have the technical skill to build our own bespoke system, which can be reconfigured dependent on the experiment to be performed. This would include novel laser sources through to cutting edge adaptive optics. Due to our skill and expertise and donations from the RS Macdonald Charitable Trust, our reconfigurable system will uniquely have the ability to image at depth, through turbid medium and in living tissue. This means that we can adapt our technology to fit the biological question to be answered, and not, as usually occurs adapt the biology to fit the technology.

MCF10A cells imaged using the super-resolution OMX microscope at SULSA Dundee, showing the actin cytoskeleton of connecting cells: Susana Moleirinho and Dr Markus Posch.

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