Improving Spatial and Chemical Resolutions in Sample Collections for Primary Amine Quantification

Quantitative analytical measurements of metabolites from the extracellular space are vital for the understanding of biological processes and more so, disease recognition. To make precise and accurate determinations, analytical method development is a key process. Careful consideration is necessary when choosing collection techniques, sample preparations, analyte detection methods, and lastly, statistical analyses. This dissertation highlights the development, characterization, and demonstration of sampling methods that increase spatial or chemical resolutions. Sampling methods and analyses of individually collected blood from the fruit fly are discussed for determinations of sample perturbation by anesthesia methods, physiologically relevant metabolites in anatomical regions, and the impact of cells on hemolymph chemical determinations. Secondly, explorations of the regulatory role of cystine glutamate transporter, xCT, in GSH synthesis and glutamate homeostasis under induced oxidative stress is highlighted with emphasis on primary amine and thiol determination by capillary electrophoresis with laser induced fluorescence. Lastly, a reduced tip technique, µ-low-flow-push-pull perfusion, for ex vivo sampling of the extracellular space of mouse hippocampal brain slices is discussed to characterize basal neurotransmitter and primary amine content. Together, these projects identify novel sampling methods to quantify chemical content in volume limited models with emphasis on increasing spatial and chemical resolutions.