Page 37 - MNU PM502 Ph. Micreo practical
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Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)
Rideal Walker test
Conditions of the test
1- The concentration of the test disinfectant and standard phenol is changed, and
the extinction time is also changed.
2- Organism: Salmonella typhi suspension.
3- Temp: 20 C
4- Subcultures are performed from both the test and phenol at intervals of 2.5, 5,
7.5 and 10 minutes.
5- The tubes are incubated for 48-72 hours at 37 C.
6- They reported that the most efficient time for a disinfectant to kill the whole
microorganism population is 7.5 min.
Practical mission:
You are provided with two flasks, one containing 100ml of phenol (Standard
Disinfectant) and the other one containing 100 ml of test disinfectant & required
to evaluate the test disinfectant according to Rideal – Walker method.
Equipments:
1. Two flasks, one containing 100 ml of 5% phenol (Standard Disinfectant) and the
other one containing 100 ml of test disinfectant.
2. Flask containing sterile distilled water.
3. 10 test tubes (sterile & empty).
4. 40 n. broth tubes (containing 5ml).
5. Wasserman tube containing the microorganism.
6. 10 ml pipette.
7. Loop.
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