Serial Dilution

What is the dilution factor when transferring 1 mL from the second test tube to the third test tube in a serial dilution?

• 10
• 0.1
• 0.01
• 100

What is the purpose of performing a serial dilution in microbiology?

• To sterilize the sample
• To decrease the concentration of a solution
• To increase the concentration of a solution
• To identify the bacteria present

What is the dilution factor when transferring 1 mL of sample to a total volume of 10 mL in a test tube?

• 0.5
• 10
• 1
• 0.1

How can the population of cells be calculated in a serial dilution experiment?

• By measuring the temperature
• By dividing the dilution factor by the volume
• By using a spectrophotometer
• By multiplying the cfu by the dilution factor

Why is it important to use sterile materials in a serial dilution experiment?

• To decrease the number of bacteria
• To speed up the process
• To increase the number of bacteria
• To prevent contamination

How can the cell population in each test tube be enumerated after making the dilutions?

• By using a microscope
• By analyzing the DNA sequence
• By counting the number of colonies
• By measuring the pH level

Which of the following materials is NOT needed for a serial dilution experiment?

• Test tubes
• Pipettes
• Petri dishes
• Bunsen burner

What does a dilution factor of 10^-3 indicate in a serial dilution experiment?

• The sample is not diluted
• The sample is 100 times diluted
• The sample is 10 times diluted
• The sample is 1000 times diluted

What is the purpose of using poor plate or spread plate techniques in a serial dilution experiment?

• To decrease the number of colonies
• To mix the samples
• To separate and count colonies
• To increase the number of colonies

What does a Colony Forming Unit (cfu) between 30 and 300 indicate in a serial dilution experiment?

• Too few to count
• Too many to count
• Not significant
• Countable