Serial Dilution

The followings are objectives of serial dilutions EXCEPT.

• To make viable colony counts.

• To produce colony forming units.

• To dilute the bacterial population.

• To identify species of bacteria.

Which of the followings is the optimum number of colonies to make viable bacterial count?

• 10-100 colonies

• 20-200 colonies

• 20-400 colonies

• 10-300 colonies

Serial dilutions are sequential ____ dilutions of a sample

• 1:2

• 1:5

• 1:10

• 1:100

If you add 1 ml culture to 9 ml diluent, this dilution is

• 1 : 1,000

• 1 : 100

• 1 : 10

When quantitating dense bacterial samples, what needs to be done before you can do a standard plate count?

• measure turbidity

• measure absorbance

• membrane filtration

• serial dilutions

If you want to create a 1:8 dilution of bacterial culture, then you add 1 ml bacterial culture to ____ diluent (media).

• 8 ml

• 7 ml

• 9 ml

• 10 ml

Juice was analyzed via serial dilution and standard plate counts. 1 ml of dilution was put on each plate. 98 colonies grew on the 1:10,000 dilution plate. The concentration of bacteria in the juice is

• 980,000 CFU/ml

• 98,000 CFU/ml

• 9,800 CFU/ml

• 980 CFU/ml

What is the primary purpose of performing a serial dilution in a laboratory setting?

• To increase the concentration of a solution

• To decrease the concentration of a solution

• To maintain the concentration of a solution

• To change the color of a solution

Tags

NGSS.HS-PS1-5

In a serial dilution, if you start with a 1:10 dilution and perform three more 1:10 dilutions, what is the final dilution factor?

• 1:100

• 1:1,000

• 1:10,000

• 1:100,000

Which of the following is a common application of serial dilution in microbiology?

• Measuring the pH of a solution

• Counting the number of bacteria in a sample

• Determining the boiling point of a liquid

• Identifying the color of a chemical