Experiment Preparation and Procedure Notes

Lab Materials

  • Pipettes:
    • Pipettes for 100 μL and 1000 μL
    • Sterile pipette tips
  • Other materials:
    • A jar of alcohol
    • A bacterial spreader

Day One Procedures

Plate Labeling
  1. Label eight plates as follows:
    • Plates labeled with group name, date, and experiment number.
    • Two plates as "A1" and "A2".
    • Two plates as "B1" and "B2".
    • Two plates as "C1" and "C2".
    • Two plates as "D1" and "D2".
Dilution Series Preparation
  1. Prepare a dilution series using five tubes:
    • Each tube will follow this sequence for preparation:
      • Tube 1: 1 mL of the stock solution + 9 mL of diluent
      • Tube 2: 1 mL from Tube 1 + 9 mL of diluent
      • Tube 3: 1 mL from Tube 2 + 9 mL of diluent
      • Tube 4: 0.1 mL from Tube 3 + 9.9 mL of diluent
      • Tube 5: 0.1 mL from Tube 4 + 9.9 mL of diluent
Dilution Factors
  1. The dilution factors (DF) for each tube are:
    • DF for Tube 1: 1.0×10−11.0 \times 10^{-1}
    • DF for Tube 2: 1.0×10−21.0 \times 10^{-2}
    • DF for Tube 3: 1.0×10−31.0 \times 10^{-3}
    • DF for Tube 4: 1.0×10−51.0 \times 10^{-5}
    • DF for Tube 5: 1.0×10−71.0 \times 10^{-7}
Diluent Utilization
  1. The diluent used in each tube can vary based on:
    • 9.0 mL or 9.9 mL of sterile water, according to the experimental requirements.
    • The type of fluid media conducive for bacterial growth, which may include:
      • Warm-melted agar
      • Water
      • Milk
      • Any type of microbiological broth containing necessary nutrients.