Page 45 - MNU PM502 Ph. Micreo practical

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

Repeat this step to prepare different concentrations of the phenol (4.5%, 4% and

3.6%).

2- Preparation of the reaction mixture: to the prepared dilutions transfer 2.5 ml

of the inoculated yeast suspension at zero time to all dilutions at 30 seconds

interval, then make the four reaction mixtures stand for 30 minutes.

3- Making subcultures from the reaction mixture: Mark the nutrient broth tubes

with the glass pencil as (5%, 4.5%, 4% and 3.6%), then take one loopfull from each

reaction mixture and inoculate it to the corresponding nutrient broth tube at 30

seconds interval.

4- Incubate the nutrient broth tubes at 37° C for 24hrs and determine the growth.

5- Repeat the same steps for the tested disinfectant (Preparation of different

dilutions 2%, 1.8%, 1.6% and 1.4% then preparation of reaction mixtures, making

subcultures and incubation).

6- Record Pc and Tc. Then you can calculate Chick – Martin (C.M.) coefficient.

Calculation of the coefficient:

C.M. coefficient = Lowest conc of phenol that kill M.O (Pc) / Lowest conc of test

disinfectant that kill M.O (Tc)

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