2 Hypotheses Alternate Hypothesis: The use of GFP is effective to measure pH level of drinks through fluorescence intensity of E. coli exposed under UV light. Bacteria in each drink will fluorescence as much as in the broth with similar pH level. (e.g. fluorescence intensity in tap water is expected to equate that of the broth with a pH level of 7). Null Hypothesis: pH level cannot be investigated through GFP fluorescence intensity. 3 Method 3.1 Development and planning When designing the procedure of the experiment, the first idea that came to mind was to use starter plates with agar. But considering how fast cross-contamination could occur if the bacteria were to have direct contact with air, it was better to use nutrient broth to grow E. coli in the calibration with known pH …show more content…
Thus, cross-contamination could be limited as much as possible by placing a cotton bud and some aluminum paper at the mouth of each conical flask. The pilot study involving Green Fluorescent Protein developed was to measure how much arabinose sugar is contained in five different drinks in the form of E414, gum Arabic, that is essentially made up of arabinose. The experiment did not work out as the arabinose content in the five drinks chosen was too little for the bacteria to glow. That failure generated the idea of varying the pH level rather than arabinose amount in order to indirectly measure, by comparison to the calibration, the pH of five other drinks. Those beverages should not contain E414 as it might affect fluorescence intensity, though insignificantly, but would still change the uncertainty of measurements. In the first developed experiment, ImageJ software was used but displayed very high standard deviations.