Page 59 - MNU PM502 Ph. Micreo practical

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

LAB 4

Disinfectant tests

4- Practical tests

• The practical tests under real-life conditions are performed after measuring

the time-concentration relationship of the disinfectant in a quantitative

suspension test.

• The objective is to verify whether the proposed use dilution is still adequate

in the conditions under which it would be used.

Examples: -surface disinfection tests

-filter paper test

Filter Paper Test

(Disc-Diffusion Method)

• The disk-diffusion method involves applying different chemicals to

separate, sterile filter paper discs.

• The discs are then placed on an agar plate that has been inoculated with the

targeted bacterium and the chemicals diffuse out of the disks into the agar.

• As the “lawn” of bacteria grows, zones of inhibition of microbial growth
are observed as clear areas around the disks.

• larger zones typically correlate to increased inhibition effectiveness of the

chemical agent.

Equipment:

1. Sterile filter paper discs
2. Test disinfectants
3. Standardized test organisms

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