Environmental Report

Are microbes all around us? To the naked eye, we might believe that microbes only exist in filth, dirty, nasty environments and poor cleanly habits. If you were to take a culture of your kitchen table or a class room desk, would you expect to find microbes? Do microbes everywhere or is it just superstition. As a lab class experiment, several samples of the different school environments will be taken to prove that microbes do exist in places we can't see and don't expect them to be in.

MATERIALS:

Petri plate containing nutrient agar (1)

Petri plate containing blood agar (1)

Normal saline test tube (1)

Cotton swab applicators (6)

Procedure: step 1

1. Label both Petri plates with name and class information.

2. Unwrap applicator, dip into normal saline till moist.

3. Using the lateral surface of the applicator and rub surface of choice.

4. Label the wrapper with the location that the sample was taken from.

5. Put the used applicator into the wrap to preserve the sample and document.

6. Repeat steps number 2-5 till a total of 4 samples have been taken.

7. Using the nutrient agar Petri plate, label the bottom with a line across the middle going vertical and horizontal. Number each section 1-4.

8. Using the swabbed applicator used prior, swab one section of the Petri plate and document.

9. Repeat number 8 till all sections of the Petri dish is swabbed with a different applicator.

10. Place the Petri dish upside-down to prevent any condensation from falling onto agar surface.

11. Using the blood agar Petri plate, label the bottom with a single line down the middle. Label each section, N=nose and the other T=throat

12. unwrap the applicator, swirl tip into nostril

13. Slightly open Petri plate, streak the swab onto the N-section of the Petri plate and document.

14. Unwrap the last applicator; swab the back of the throat to the point of the gag reflex.

15. Slightly open the Petri plate, streak the swab onto the T-section of the Petri plate and document.

16. Put both the nutrient and blood agar Petri plates into the incubator at 37◦c for 24-48 hours.

MATERIAL:

Bunsen burner

Inoculating loop

Glass slides (12)

Distilled water bottle

Clothes pin

Flame striker

Paper towels

Incubated Petri dishes (2) blood/nutrient agar

Crystal violet dye

Iodine (mordant)

Alcohol-acetone

Safranin dye

Procedure: step 2

1. Remove both the nutrient and blood agar from the incubator.

2. Observe and record the intensity of growth and numbers of the different colony types of each source of the specimen.

3. Connect the Bunsen burner to the gas outlet; pull the lever down to open the gas valve.

4. Quickly use the flame striker and lite flame onto Bunsen burner.

5. Add one small drop of distilled water to the center of the glass slides, till all 12 are done.

6. Flame the loop till it turns bright red/orange in color.

7. Touch the loop onto the outer edge of the Petri plate to cool the loop. Use the loop and take one sample of colony A in one section. Smear it onto the slide and air dry.

8. Flame the loop, cool and take one sample of colony B in that same section. Smear it onto the slide and air dry.

9. Repeat steps numbers 6-8 till all 12 slides are completed.

10. Start

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