Uji Coliform dengan Metode MPN

Summary

This video explains the process of performing a coliform bacteria test using the Most Probable Number (MPN) method. It involves preparing test tubes with sterile water, labeling them, and adding samples to the media. The samples are incubated at 37°C for 24 hours, then observed for bubble formation or color changes, indicating bacterial growth. Positive results show contamination, while negative results show no bacterial growth. The final results are compared with the MPN table to determine the contamination level of the samples. This method is crucial for monitoring water quality and ensuring safety.

Takeaways

• 😀 The procedure being conducted is a coliform test using the MPN method.
• 😀 Sterile distilled water (aquadest) is used in each test tube.
• 😀 The test involves multiple tubes labeled X1, X2, X3, Y1, Y2, Y3, Z1, Z2, Z3 for the suspension and media.
• 😀 A micropipette is used to transfer 1 milliliter of sample into the media-filled tubes.
• 😀 The bacterial suspension is carefully transferred into the labeled test tubes (X, Y, Z series).
• 😀 After transferring, the test tubes are disposed of and prepared for incubation.
• 😀 The incubation step is conducted at 37°C for 24 hours.
• 😀 After 24 hours, the samples are observed for gas bubbles or color changes to identify positive results.
• 😀 Positive results are indicated by the presence of gas bubbles or a color change in the medium.
• 😀 Negative results show no gas bubbles and no color change, indicating no coliform presence.
• 😀 The final result is compared with the MPN table to determine the coliform count in the sample.

Q & A

What is the purpose of the MPN test mentioned in the transcript?

The MPN (Most Probable Number) test is used to detect the presence of coliform bacteria in a water sample.

What does the script suggest about the role of 'aquadest' in the test?

Aquadest (sterile water) is used to ensure that the test media is free from external contaminants, providing a controlled environment for the bacterial test.

What does the 'Brilliant Green Balbot' media used in the test help to identify?

The Brilliant Green Balbot media is used to culture and test for coliform bacteria, helping to differentiate bacterial growth by color and gas production.

What is the significance of labeling the test tubes with 'X1', 'X2', 'X3', 'Y1', 'Y2', 'Z1', 'Z2' in the process?

The labeling of the test tubes allows for proper identification of each sample as it undergoes different stages of the test, ensuring accuracy and clarity during the incubation and result observation.

What happens after the bacteria suspension is prepared and transferred into the test tubes?

The prepared bacterial suspension is transferred into the labeled test tubes, with each tube receiving a specific volume to ensure proper testing at each stage. Afterward, the samples are incubated.

What is the incubation temperature and duration mentioned in the transcript?

The samples are incubated at a temperature of 37°C for 24 hours.

How can one determine if a test tube result is positive for coliform bacteria?

A positive result is indicated by the presence of bubbles or a color change in the medium, signifying bacterial growth and gas production.

What is the significance of the negative results shown in tubes 'Y1', 'Y2', and 'Z3'?

Negative results are identified by the absence of bubbles and no color change, indicating no coliform bacterial growth in those specific tubes.

How does the result from the 'X1', 'X2', 'X3' tubes compare to the other tubes?

The 'X1', 'X2', 'X3' tubes showed positive results as they displayed bubbles, indicating bacterial growth, whereas other tubes like 'Y1' and 'Z3' were negative.

What does the script mean by comparing the results with the MPN table?

After observing the results, the data is compared with the MPN table to estimate the most probable number of coliform bacteria in the sample, helping to assess its safety and quality.