1. University of Puerto Rico<br />Cayey Campus<br />Jessica Díaz Rivera<br />804-10-2076<br />Prof. Elena Gonzalez<br />Laboratory #3: Water sampling, testing, and statistical application<br /> The research of Dr. Javier Arce was about taking water samples in different houses to analyze-which one is contaminated. First he took water samples and placed them in sterile bottle at different temperatures, especially on ice to avoid contamination, because bacteria grow very fast at room temperature. One of the things that we have to do to analyze the water is select a technique like: Heterotrophic Plate Count, Tube Fermentation Technique, and Defined Substrate Technologies. Also in a bottle of water you need to add Idexx Colilert to identify bacteria. You have to decrease the water temperature to 35 degrees Celsius, place in the Quanti Tray in the Quanti-Tray Sealer, and later in the incubator. By using a UV light you will see the presence of coliforms after 24 hours. Positive E. coli are fluorescent and positive coliforms are yellow. The part of statistical application was about the types of statistical quantifications, statistical analysis and types of errors. We learned how to use Excel Program to know the variance, average and standard deviation, and analyze some data doing tables and graphs in Excel. To conclude, we learned how to take water samples and how to analyze a lot of data using Excel Program. <br />