ABSTRACT A major cause of genetic disease is associated with chromosomal imbalances, such as deletions (subtelomeric, terminal and interstitial), duplications, and unbalanced translocations present in a particular chromosome segment. The diagnosis of many genetic diseases remains problematic. This is due in part to difficulty in detection of DNA copy number changes, when these are either too small (for conventional cytogenetics) or too large, for standard molecular approaches. From this viewpoint, the development of new screening methods with improvement of resolution is very important. Genome-wide screening at a molecular level began to appear feasible with the completion of the human genome sequence. From this beginning, high-resolution whole-genome technologies could be envisaged, to improve the diagnostic detection rate for even the smallest of chromosomal imbalances. The technique known as ???array-based comparative genomic hybridization??? (array-CGH) does allow such a high-resolution screening, by use of reference DNA probes, printed onto arrays, thus consisting of thousands of genomic clones. In this study we extensively investigated many major aspects of array-CGH technology from preparation of microarray probes and printing microarray slides, to a development of custom protocols and custom softwares for data processing and analysis. We have trailed several array types and protocols, direct and indirect DNA labelling techniques and, as a result, we have achieved the practical application which was our target at the onset of this work. This was to use a modified array-CGH method, as a robust and economical diagnostic test in detection of deletions and duplications within the human genome. The project has been successful, in terms of one very important outcome: The laboratory in which this work was done is now the leading clinical diagnostic lab in this field, in Australia???s most populous state of New South Wales. That achievement would not have been possible without a very lengthy period of developmental work, including that which comprises much of this thesis.

The application of electronic-resonance enhanced (ERE) coherent anti-Stokes Raman scattering (CARS) for the detection of nitric oxide (NO) and acetylene (C2H2) is experimentally demonstrated and the effects of various parameters on the ERE CARS signal investigated. In addition, the detection of dipicolinic acid (DPA) using “normal” CARS is demonstrated. For NO detection, the frequency difference between a visible Raman pump beam and Stokes beam is tuned to a vibrational Q-branch Raman resonance of the No molecule to create a Raman polarization in the medium. The second pump beam is tuned into resonance with the rotational transitions in the (1,0) band of the A2Σ+-X2Π electronic transition at 236 nm, and the CARS signal is thus resonant with transitions in the (0,0) band. A NO gas cell was used for the experiment to detect NO at various pressure levels. A significant resonant enhancement of the NO CARS signal was observed and good agreement between calculated and experimental data was obtained. For C2H2 detection, ERE CARS experiments were performed in a roomtemperature gas cell using mixtures of 5000 ppm C2H2 in N2. Visible pump and Stokes beams were used, with the frequency difference between the pump and Stokes tuned to the 1974 cm-1 Ϡ2 Raman transition of C2H2. An ultraviolet probe beam with the wavelengths ranging from 232 nm to 242 nm is scattered from the induced Raman polarization to generate the ERE CARS signal. The effects of probe wavelength and pressure on signal generation are discussed. CARS was used to detect the 998 cm-1 vibrational Raman transition from a sample of polycrystalline DPA. The transition is the breathing ring vibration in the pyridine ring structure in the DPA molecule. The DPA 998 cm-1 transition is detected with excellent signal-to-noise ratio and the full-width-at-half-maximum is very narrow, approximately 4 cm-1.

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No description available.

ABSTRACT A major cause of genetic disease is associated with chromosomal imbalances, such as deletions (subtelomeric, terminal and interstitial), duplications, and unbalanced translocations present in a particular chromosome segment. The diagnosis of many genetic diseases remains problematic. This is due in part to difficulty in detection of DNA copy number changes, when these are either too small (for conventional cytogenetics) or too large, for standard molecular approaches. From this viewpoint, the development of new screening methods with improvement of resolution is very important. Genome-wide screening at a molecular level began to appear feasible with the completion of the human genome sequence. From this beginning, high-resolution whole-genome technologies could be envisaged, to improve the diagnostic detection rate for even the smallest of chromosomal imbalances. The technique known as ???array-based comparative genomic hybridization??? (array-CGH) does allow such a high-resolution screening, by use of reference DNA probes, printed onto arrays, thus consisting of thousands of genomic clones. In this study we extensively investigated many major aspects of array-CGH technology from preparation of microarray probes and printing microarray slides, to a development of custom protocols and custom softwares for data processing and analysis. We have trailed several array types and protocols, direct and indirect DNA labelling techniques and, as a result, we have achieved the practical application which was our target at the onset of this work. This was to use a modified array-CGH method, as a robust and economical diagnostic test in detection of deletions and duplications within the human genome. The project has been successful, in terms of one very important outcome: The laboratory in which this work was done is now the leading clinical diagnostic lab in this field, in Australia???s most populous state of New South Wales. That achievement would not have been possible without a very lengthy period of developmental work, including that which comprises much of this thesis.

No description available.

by Lee Kwan-Chuen. / Title also in Chinese. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography : leaves 86-88.

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No description available.

No description available.