Micro-irradiation systems are used to analyse the effect of ionizing radiation at the cellular and tissue level, targeting individual cells within a population with a controlled low dose. Cell survival experiments using micro-irradiation systems are limited by factors including: 1) the radiation attenuation and optical properties of the chosen cell dish substrate, 2) the registration of the cell dish before and after irradiation or between multiple imaging modalities and 3) the analysis of the cell or colony growth after irradiation. In this thesis, a set of tools have been developed to improve micro-irradiation experiments and to increase the accuracy of information provided by the cell survival data. The first contribution, the substrate cell dish evaluation, provides a set of characteristics defining the substrates used for micro-irradiation experiments based on minimal energy loss and optical clarity using unstained cell imaging. The second contribution was the development of a novel and low cost fiducial marking device for micro-irradiation experiments using an 808 nm laser and providing marks suitable for imaging with multiple modalities. The minimum focused spot diameter was calculated as 22.9 urn and the device was used to create fiducial marks with diameters ranging from 20 urn to 130 urn. The third contribution, the development of a cell counting methodology for use with a lens-free imaging device, has been shown to accurately count thousands of cells suitable for immediate analysis. Approximately 1000 cell colonies, containing 17 729 cells on 11 cell dishes were used for testing and training for automatic cell counting. Validation of the cell counting method showed that 76% and 89% of the cell colonies were counted within a ± 20% and ± 30% error of the ground truth, respectively. Further development of the fiducial marking device, by modifying the choice of laser and making it suitable for multiple types of cell dish substrates, would increase the applications of the device. Development of the cell counting methodology for different cells line, and for cells grown on multiple types of substrates, would make the system suitable for analysis of a wide variety of cell survival studies. The cell counting methodology, applied to the CyMap lens-free imaging device, has the potential to be an extremely useful and cost effective tool for cell survival studies.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:589627 |
| Date | January 2011 |
| Creators | Flaccavento, Giselle |
| Contributors | Vojnovic, Boris ; Noble, J. Alison |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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