Collections Lab
PURPOSE
This lab is to observe the differences of bacterial growth of different people's nostrils.
HYPOTHESIS
I predict that Ace (subject 3) will have the most bacterial growth because he has the largest nostrils of all the subjects as well as the longest nose hairs which are able to trap bacteria better.
MATERIALS
- tap water
- cotton swabs
- petri dish with agar
- incubator
- wax pencils
- inoculation loop
- dH2O
- slides
- microscope
- bunsun burner
- flint lighter
- paper towel
- slide holder
- 100mL beaker
- Crystal Violet
- Iodine (IKI)
- 95% ethanol
- safrinin
- table disinfectant
- tape
METHOD
- Draw lines on the bottom of the petri dish to split it into four quadrants using a wax pencil.
- Label each quadrant in the corner 1-4 using the wax pencil.
- Have one of the quadrants be the designated control.
- Moisten a cotton swab using tap water without touching the ends.
- Swab the inside of the right nostril in a circular fashion, going around twice.
- Swab the cotton swab into the designated section of the petri dish without opening it all the way in a straight line 3 times.
- Dispose of cotton swab.
- Repeat steps 4-7 with other subjects.
- Tape the lid of the petri dish to the base to it remains closed.
- Place the petri dish in the incubator for a few days.
- Remove petri dish from incubator and preform Gram staining process using all sterile techniques.
- Examine the slides of bacteria under a microscope using a magnification of 400x total.
RESULTS
ANALYSIS
All the bacteria on the petri dish were found to be gram positive including the unknown bacteria that appeared to be burnt due to the incubator. All four of the bacteria tested appeared to be the same type of bacteria due to the similarities of the gram stained bacteria. Under analysis, Vanessa's (mine) bacteria appeared ti have the most chains compared to the other slides, however, it still contained a large amount of single coccus bacteria. Kathleen, Ace and the unknown bacteria all appeared to have single coccus bacteria with few small chains.
CONCLUSION
My hypothesis proved to be incorrect because Vanessa's (my) bacteria had the most growth compared to the other sections. Although the amount of growth was different, all the bacteria appeared to be the same type because the bacteria were all swatched from the inside of people's nose. A problem with our lab was part of our bacteria burnt from the incubator since it was place at the very back. This could have been prevented by not placing the petri dish right up against the back of the incubator. If I were to further examine my hypothesis, I would be more cautious in repeating each step the exact same each time as well as using a micro scope of a higher power.