Thesis presented December​ 03, 2009

Abstract:
Time-lapse microscopy is crucial in cell biology, but often expensive and it also requires lab space. My Ph.D. project aims at developing a miniaturized video microscope​. The objective is to eventually parallelize, but also to optimize integration with other sensors on a lab-on-a-chip. The considered approach for miniaturization is to suppress objectives and to observe cells directly on the sensitive surface of an image sensor in a mode called “contact imaging”. The microsystem elements have been selected and prepared to protect the sensor electronics from the aqueous culture medium, and to favor physiological conditions for the cells of interest. The observation has been optimized in reference to the images given by classical microscopy. Time-lapse monitoring of cellular events (mitosis, motility, apoptosis...) has been demonstrated with our prototype. The microsystem elements have been characterized to better understand the underlying mechanisms of image formation in order to optimize them. Our system resolution (11.2 µm) gives access to cellular morphology, and is potentially upgradable by using smaller pixels. An interesting improvement for cell biology would be the ability to detect luminescence or fluorescence.

Keywords:
Time-lapse microscopy, image sensor, cell culture, adherent cells, contact imaging, lab-on-a-chip

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