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Coherently Advanced Tissue and Cell Holographic Imaging and Trapping (CATCHIT)
Date du début: 1 mai 2010, Date de fin: 30 avr. 2015 PROJET  TERMINÉ 

We envisage a new generation of dynamic holographic laser tweezers and stretching tools with unprecedented spatial control of gradient and scattering light forces, to unravel functional mysteries of cell biology and genetics: Based on our recently developed, highly successful and widely recognized amplitude and phase shaping techniques with cascaded spatial light modulators (SLM), we will create new holographic optical manipulators consisting of a line-shaped trap with balanced net scattering forces and controllable local phase-gradients. Combining these line stretchers with spiral phase contrast imaging or nonlinear optical microscopy will allow quantitative study of functional shape changes. The novel tool is hugely more versatile than standard optical tweezers, since direction and magnitude of the scattering force can be designed to precisely follow the structure. In combination with conventional multi-spot traps the line stretcher acts as a sensitive and adaptable local force sensor. In collaboration with local experts we want to tackle hot topics in Genetics, e.g. search for force profile signatures in regions with Copy Number Variations. Possibly the approach may shed light on basic physical characteristics such as, for example, chromosomal fragility in Fra(X) syndrome, the most common monogenic cause of mental retardation. The new design intrinsically offers enhanced microscopic resolution, as SLM-synthesized apertures and waveforms can enlarge the number of spatial frequencies forming the image. Ultimately, nonlinear holography can be implemented, sending phase shaped wavefronts to target samples. This can, e.g., be used to push the sensitivity of nonlinear chemical imaging, or for controlled photo-activation of targeted regions in neurons.