This is a two-part exercise on chemical and physical control of microbes. In Part I normal skin flora organisms will be isolated and used in a disc diffusion assay to test the efficacy of various household products and antibiotics. Lab skills mastered in Part I will be employed in Part II, an investigative exercise where factors affecting the effect of UV exposure on Serratia marcescens will be determined through group-designed procedures. Experimental set-ups will be exposed to a UV lamp in a biosafety hood. Growth after incubation at room temperature will be recorded and compared to results from other groups.