A Manual Kinetic Assay in a Fixed Yeast Model for Drug Discovery

Manual cell counting assays are often considered as a gold standard in some applications because of direct observation of results. Here a manual kinetic cell counting method is used to evaluate the efficacy of reagents to unclump cells in a fixed yeast ( Saccharomyces cerevisae ) model. Clumped cells are more dangerous than single cells in many human venues such as cancer spread, thrombocytic blockages and biofilm infectivity. In this study percentage of single cells are analyzed over time in the presence or absence of specific reagents and the number of cell clumps and cells per clump are also assessed. The results show that when the percentage of single cells increases, the number of clumps and cells per clump decrease, helping to validate the assay. These findings suggest that this assay can be a gold standard for evaluating the effects of specific reagents on cell unclumping in a model system that can be used in drug discovery investigations. This study is part of a program that won a U.S. Presidential Award for science mentoring presented by President Obama at the White House. The experiments are easily accomplished by undergraduate students and can be done by research classes without background in complex science methodology.