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During the Spring 2016 semester I have worked in conjunction with my one team member to research and develop a design or prototype of a microbe detector. Since we are a new team we will spend a good amount of time researching microbial detection techniques. Although this is time consuming it is a necessary step in creating a product. In order to make our product applicable to the water treatment plant sites, we will also need to specify our research for low resource detection. There are many existing methods of microbial detection,but few that can function in the low resource settings that AguaClara serves. After researching, I took the parts of multiple methods to design the sliding colony counter with the gelatinous thickened media. This semester was mostly dedicated to developing the right media with the right gelatin concentration. The experiments that I ran tested the ability of gelatin to mix in media, the most optimal gelatin concentration, the ability of microbes to grow in different gelatin concentrations and media+gelatin behavior in different containers. The different gelatin concentrations tested were 1g//100ml, 2.5g/100ml, 5g/100ml, 1g/20ml, 2.5g/20ml, 3.75g/20ml, 5g/20ml. With the smaller volume, the 1g seemed to be plenty but for the larger volume, even the 5g did not seem to be enough to thicken all of the media. The purpose of these gelatin experiments was to determine how media could be thickened in order to slow down bacterial movement (swimming) to allow the growth of individual colonies. This way, the number of bacteria present in the water could be determined by the number of colony forming units (CFUs).
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