10 Questions
What is the purpose of the disk-diffusion assay method?
To assess the effectiveness of chemicals on inhibiting microbial growth
In the disk-diffusion assay, what contributes to the size of the zone of inhibition?
The ability of the chemical agent to diffuse in the agar
How are zones of inhibition observed in a disk-diffusion assay?
As cleared areas or halos around the paper disks
What is typically associated with larger zones of inhibition in a disk-diffusion assay?
Increased inhibition effectiveness of the chemical agent
How is the diameter of the zone of inhibition measured in a disk-diffusion assay?
With a ruler in millimeters
What is the purpose of applying different chemicals to sterile filter paper disks in the disk-diffusion assay?
To test the effectiveness of disinfectants or antiseptics against bacteria
In the disk-diffusion assay, what contributes to the appearance of zones of inhibition?
Diffusion of chemicals from the paper disks into the agar
How does the size of the zone of inhibition typically correlate with the effectiveness of a chemical agent in the disk-diffusion assay?
Larger zones indicate higher effectiveness
What does the diameter measurement of the zone of inhibition represent in a disk-diffusion assay?
The level of effectiveness of the chemical against bacteria
What effect do water-soluble agents have on the size of the zone of inhibition in a disk-diffusion assay?
They create larger zones of inhibition
Study Notes
Disk-Diffusion Assay
- The disk-diffusion assay involves applying different chemicals (e.g., disinfectants or antiseptics) to individual sterile filter paper disks.
- The disks are placed on an agar plate that has been inoculated with a bacterium of interest and incubated for 24-72 hours.
- During incubation, chemicals diffuse into the agar, and zones of inhibition of microbial growth appear as cleared areas or halos around the paper disk.
- The size of the zone of inhibition is influenced by factors such as whether the agent is water soluble and able to diffuse in the agar.
- Larger zones of inhibition typically correlate to increased inhibition effectiveness of the chemical agent.
- The diameter of the zone of inhibition is measured in millimeters using a ruler to quantify the effectiveness of the chemical agent.
Learn about the disk-diffusion assay method used to test the effectiveness of chemicals like disinfectants and antiseptics against bacteria. Understand the process of applying chemicals on filter paper disks, placing them on agar plates, and observing zones of inhibition of microbial growth.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
