CFU COUNT & ANALYSIS

A) CFU COUNT

• • Count the visible CFU´s
    
    • Remove plates from the incubator
    • Count the visible CFU´s on each plate to obtain a numerical value expressed in CFU/ml

B) CALCULATIONS

• • Convert CFU/ml to CFU/gr
    
    • Multiply the CFU/ml by 10 ml (Neutralizer) and divide by 0.4 gr (weight of the test sample)
    • Repeat this process for each sample
  • Calculate averages
    
    • Calculate the geometric means of the values obtained from duplicate samples
  • Calculate the percent reduction
    • Using one of the formulas provided by the ASTM E3160 Test Method, calculate the percentage reduction of the bacterial activity
  • Visualize data to compare the results obtained from the different samples