Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 249-259).

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1987. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Bead count rate (BCR) monitoring successfully identifies pipetting error during single platform enumeration. Enumeration beads are a stable constant in each patient’s sample and if these can be multitasked to monitor overall flow cytometer operation in a model of continuous quality control (CQC), they could reveal further details of flow cytometer operation and fulfill more quality assurance functions than identify pipetting error alone. Methods The CQC model used manufacturer recommended quality control procedures daily. In addition, methods were developed to monitor flow cytometer fluidics and electronics as well as sample preparation to standardise and extended quality monitoring. Sample-to-sample CQC included monitoring BCR, selected time, optical and fluorescence histograms as well as FPCV and MCN. This model also incorporated diligent monitoring of BCR patterns to detect instrument malfunctions. Post standardisation and implementation of the CQC model, an extended EQA exercise assessed bias between standardised CD4 counting methods and determined a ‘near true’ CD4 count to use as a calibrator. Conclusion The proposed CQC model standardised overall flow cytometer and automated sample preparation systems and, established imprecision reference intervals for each aspect of testing (fluidics <3%, sample preparation 2-4% and protocol and electronics <2%). Further BCR pattern recognition was used to identify instrument malfunctions in real-time and, longitudinally for pro-actively identifying imminent breakdowns. CD4 counts were calibrated to consensus mean ‘near true’ counts on two flow cytometers in the Reference Laboratory.

A research report to the Faculty of Health Sciences, University of Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master Medicine in branch of Haematology / Donor specific crossmatching is performed prior to renal transplantation in order to determine the presence of pre-existing antibodies against donor HLA antigens which can result in hyperacute rejection. Flow cytometric crossmatching is reported in the literature to be a more sensitive and objective method of testing than the complement dependent cytotoxicity (CDC) method that is currently used in the Gauteng Province. A prospective analysis of the flow cytomeric crossmatch (FCXM) assay using the Luminex technology as the reference method was conducted. Forty-three samples were analysed. The T cell crossmatch (using a cutoff value of 2) revealed a sensitivity of 66.7%, a specificity of 83.8%, a positive predictive value (PPV) of 40% and negative predictive value (NPV) of 93.9%. The B cell crossmatch (using a cutoff value of 5) gave a sensitivity of 100%, specificity of 92.7%, and a PPV and NPV of 40 and100%, respectively. In addition, a retrospective analysis of clinical data for all patients transplanted during the period January 2008 to May 2009 was performed. Of a total of 50 patients assessed post transplant, none of the patients showed signs of hyperacute rejection, while twelve percent (12%) of patients revealed signs and symptoms suggestive of acute rejection. The validation of the flow cytometric crossmatch analysis was complex as there is no gold standard reference method. The assay was validated based on the clinical relevance of its high negative predictive value and the absence of hyperacute rejections in the clinical follow up. The rate of acute rejection found in this study is similar to that reported in literature.

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A method for measuring cell concentration and identity based on flow cytometry (FCM) and fluorescent marking is developed and subsequently compared with traditional plating based methods, with regards to performance, economy and ergonomy. The emphasis is on competitive growth of bacteria under antibiotic stress, but the technique could be used in any situation requiring fast, high throughput counting and identification of cellular populations. The method needs further development, but shows potential as a parallelizable and fast alternative to plating.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 127-134).