Team:Bielefeld-CeBiTec/Notebook/Journal/rMFC/Jun

From 2014.igem.org


June

  • Initial cultivation experiments with neutral red
    • This week we wanted to test the properties of neutral red during a cultivation on a small scale
      • Cultivation of the E. coli strain with porines (attempt 1) and wildtyp as control (attempt 2) in LB-medium with 100 µM neutral red
      • pH was set up at 8.75
      • Results
        • Attempt 1 turned red (pH = 7.495)
        • Attempt 2 remained yellow
  • Reduction and oxidation of neutral red
    • This week we checked the properties of neutral red under oxidizing and reducing conditions by adding chemical agents
      • Reducing agent: sodium dithionite
        • Red solution got reduced and turned colorless
        • Got oxidised by air again afterwards
      • Oxidizing agent: hydrogen peroxide
        • Red solution stayed red
        • Yellow solution stayed yellow
      • Conclusion: the color of the solution depends on the pH
  • Further cultivation experiments with neutral red
    • This week we cultivated E. coli in LB-medium with 100 µM neutral red which was reduced by different concentrations of sodium dithionite before
      • Attempts and controls
        • Negative controls:
          • 0 µl of sodium dithionite
          • 100 µl of sodium dithionite
          • 200 µl of sodium dithionite
          • 500 µl of sodium dithionite
        • Positive control:
          • 0 µl sodium dithionite with E. coli
        • Attempts:
          • 100 µl sodium dithionite with E. coli
          • 200 µl sodium dithionite with E. coli
          • 500 µl sodium dithionite with E. coli
      • Results
        • Negative controls: all controls got colored probably through oxidation by air
        • Positive control: turned yellow and turbid probably because of alkaline conditions and high cell density
        • Attempts: all attempts turned red but no turbidity is visible probably because sodium dithionite could be toxic to the cells