Screening Bioactive Molecules In Tetrahymena thermophila Using Phagocytosis Determined By Flow Cytometry

The evaluation of molecules that have potentially bioactive significance is an expanding field, but current screening assays are expensive and time consuming. Mammalian cell-based assays require aseptic techniques, complex media and long generation times. This thesis reports on an assay that incorporates Tetrahymena phagocytic ingestion and flow cytometry to evaluate several potentially bioactive molecules. Several factors that influenced optimal and reproducible results were analyzed. Seven potentially bioactive molecules (serotonin, norepinephrine, dopamine, morphine, colchicine, mexiletine and procainamide) were evaluated to determine their effect on phagocytosis by Tetrahymena. Assay results indicated that the phagocytic rate was unaffected by serotonin, norepinephrine, dopamine, and morphine but inhibited by colchicine, mexiletine and procainamide. The analysis of the data indicated that acclimation time, temperature, cell concentration, and cell wash media affected assay consistency. This assay can be used to screen for bioactive molecules