2. Gently squeeze the gelled media to the bottom of the

(Dip side) pouch, up to ‘SQZ’ mark.

3. Hang the pouches vertically’using a hanging rod in a

boiling water bath (at 100oC) with the ‘DIP side into

the water and the water level up to the ‘MAX’ mark,

for 10 minutes. Ensure that the heat source is not

directly applied to the pouch. Retrieve the pouches

after 10 minutes. (In case rod hanger is not used for the

pouches, remove the pouches using forceps/tongs).

After retrieving the pouch it should be dried diligently

with gauze and then disinfected. Any residual water

from the water bath should not be allowed to drip on

to the poured plate to avoid contamination.

4. Wipe dry the pouch corner at the ‘CUT’ mark and

disinfect with 70% isopropyl alcohol (IPA).

5. Cut the pouch across the ‘CUT’ mark with disinfected

scissors.

6. Pinch open the opening at the ‘CUT’ mark, squeeze

and pour out media aseptically into a sterile 9 mm

(diameter) petri dish, taking care not to splash or form

air bubbles while pouring.

7. Cover the petri dish and allow the poured media to set.

8. The poured plate is now ready to use.

9. The samples should be collected and processed

aseptically before plating.

Interpretation of Results

1. Gram stain, biochemical or serological studies

should be performed for the characterization and

identification of the growth.

830 Concise Book of Medical Laboratory Technology: Methods and Interpretations

2. For CLED and MacConkey agar the microorganisms

can be identified as shown in Table 27.1.

3. For susceptibility tests on Mueller Hinton (MH) agar

the size of the zone of inhibition corresponds to the

sensitivity of the microorganism to the particular

antibiotic.