Measuring Growth and the Cycle

Measuring Growth and the Cycle

1. Concentration= Counting

2. Optical Density= spectronometer

3. Coulter counters= potential across an electrode, succession of pump, no.of cell

4. Live and dead cells

   • Fluorescence: 2 Stains
     • SYT09= green (live)
     • Propidum iodide= red (Dead)

5. Cytometry: counts and sorts live and dead cells

6. Viable count cells

   • inoculate
     • solid media
       • count
   • Non culturable
     • immunoluorescence
       • Appear elongated

7. Serial Dilution= easier to count

8. Lag phase accounts of a period of adjustment

   • Exponential phase= balanced growth
     • Stationary phase= Nutrients exhausted, change in gene expression
       • Death (lysis)

9. Chemostat= limiting supply of nutrients, growth rate determined by media flow