Steps in Preparation of Culture Media

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Lay, Janine
Group #5
December 4, 2012

Experiment 1:
Preparation of Culture Media
Materials:

Erlenmeyer Flasks (2 pcs.)
Petri dishes (11 pcs.)
Cotton stopper
Aluminum foil
Masking tape
NA powder
PDA powder
Pentel pen
Stirring rod
Casserole
Electric stove
Pressure cooker/ autoclave

Steps in Preparation of Culture Media:
1. Calculate the total amount of media needed for the experiment (15ml for plates, 5-7 mL for tubes). 2. Weigh the required amount of powder needed to dissolve in distilled water (based on the manufacturers specification in the container). 3. Dissolve the powder using the stirring rod, cover, cotton stopper and label. 4. Place in water bath (do not let it boil) to dissolve the powder completely (solution should be clear). 5. Sterilize in autoclave/pressure cooker for 121°C x 15psi x 15mins. 6. Let the medium to cool and dispense in appropriate container. Note: in the tube media, dispense the medium first and then sterilize. 7. Wrap with paper and place in refrigerator (if will not be used at once).

Lay, Janine
Group #5
December 4, 2012

Experiment 2:
Normal Flora of the Body

Materials:
NA plates
Sterile cotton swabs
Tube containing sterile water
Alcohol lamp

Procedure:
1. Divide the plates into 2 sections by drawing a line in the bottom of the plates (except for 1 plate). 2. Wet the cotton with the sterile water then rub gently over areas of the body assigned each group. 1 and 2 – mouth , cheek, nose, ear, nape

3 and 4 – mouth, between toes and fingers, arm, throat
5 – mouth, ear, between fingers , nose, arm
3. Swab the agar plates direct with the cotton swab by simple streaking. 4. Label the plates and incubate for 24 hours.
5. Examine the plates (note the colonies).

Experiment #2Normal Flora of the Body|
NA|
Area Sampled| Color| Whole colony appearance| Margin| Elevation| Texture| No. of this type| 1. Mouth| Cream| Circular| Entire| Flat| Smooth| 4|
2. Betweenfinger| Cream| Circular| Entire| Flat| Smooth| 5| 3. Arm| CONTAMINATED – NO GROWTH|
4. Nose| Cream| Circular| Entire| Flat| Smooth| TNTC| 5. Ear| CONTAMINATED – NO GROWTH|

Lay, Janine
Group #5
December 4, 2012

Experiment 3:
Microbes in the Environment

Materials:

4 NA and 4 PDA plates
Inoculating loop
Alcohol lamp
Water from fountain
Water from home

Test tubes
Distilled water
Soil
Pond water
Water from faucet
Procedure:
A. Soil
1. Collect 1gm of soil and place in the test tube with 5ml sterile water. 2. Mix soil suspension by rolling the tube between palms. B. Water
1. Collect directly into tubes (5ml).
C. Air
1. Select a place in our out of the room and expose plates for 30 minutes (1NA & 1PDA). 2. Cover the plates immediately after the treatment.
Streaking in Agar plates (Soil and Water)
1. Flame sterilize the loop before and after.
2. Streak a loopful of water and soil suspension in one plate of NA and PDA. 3. Inoculate for 24 hours.

Experiment #3Microbes in the Environment|
NA|
Area sampled| Color| Whole colony appearance| Margin| Elevation| Texture| No. of this type| 1. Air| Yellow| Circular| Entire| Raised| Smooth| 3| | Cream| Circular| Entire| Flat| Smooth| 5|

| white| Circular| Entire| Flat| Rough| 4|
2. HomeWater| CONTAMINATED – NO GROWTH|
3. Faucet| CONTAMINATED – NO GROWTH|
4. Fountain| CONTAMINATED – NO GROWTH|
5. Soil| CONTAMINATED – NO GROWTH|
6. Pond| CONTAMINATED – NO GROWTH|
PDA|
Area sampled| Color| Whole colony appearance| Margin| Elevation| Texture| No. of this type| 1. Air| White| Filamentous| Filamentous| Raised| Rough| 5| | Cream| Circular| Entire| Flat| Smooth| 3|

| White| Circular| Entire| Flat| Smooth| 2|
2. Soil| Cream| Circular| Entire| Raised| Smooth| TNTC| 3. Pond| White| Irregular| Undulate|...
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