Page 94 - MNU PM502 Ph. Micreo practical

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

LAB 8

Determination of MIC by agar dilution method

The main advantage of the agar dilution is the option to test a large number of

bacterial isolates simultaneously under exactly identical conditions

Practical mission:

You are provided with certain antimicrobial agent (stock solution) and required to

determine its MIC by agar dilution method.

Equipments:

1) empty sterile test tubes.

2) Automatic pipettes.

3) sterile Petri dishes (15cm diameter).

5) Test tube containing sterile saline.

6) Test tube containing the initial conc. of the antibiotic (A).

7) Flask containing 25 ml of melted agar.

8) Wassermann tube containing the test M.O.

Steps:

• Melt the agar and cool the medium to 50 ̊C

• calculate the amount of antibiotic solutions (10, 1 and 0.1 mg/l) needed. The

Table below gives an example of the volumes needed for a concentration range

between 0.125 and 128 mg/l for one 25 ml agar plate per concentration.
81