Page 60 - MNU PM502 Ph. Micreo practical

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

4. Sterile cotton swabs
5. Forceps

6. Nutrient agar plates
7. Ruler
Practical mission:

You are provided with different test disinfectants and various standardized test

organisms, determine which of the disinfectants is more effective against each

organism.

Steps:
1. With a sterile forceps, soak discs of filter papers in each of test disinfectants

(a disc per disinfectant)

2. Transfer discs to clean paper to drain excess solutions.

3. A sterile cotton swab is dipped into the inoculum and remove excess medium
by pressing the swab onto the wall of the tube.

4. Swab the surface area of the plate completely by rotating the plate.
5. Allow the plates to dry for 5 minutes so that the medium absorbs the

inoculum properly.
6. Firstly, sterilize the forceps with alcohol before picking up paper discs.

7. Discs should be placed at a distance of 24mm.

8. Lightly touch each disc with forceps to ensure that it is in good contact to

avoid misplacement.

9. Incubate the plate upside down for 24 hours at 37ºC.

10. After 24 hours of incubation, use a ruler to measure the zone of inhibition in

millimeters and include the diameter of the disc in the measurement.

Results

Disinfectants with larger zones are more effective.

47