Lab Day 1
Experiment 1: Hand washing experiment
Materials:
- Nutrient agar plate
What we are doing and why?
- What: Before washing our hands we each put our thumbprint on a nutrient agar plate. The plate was divided in half.
Emma's prints are on the right. Hannah's prints are on the left.
Before prints are on the top and after prints on the bottom.
We put the plate in the incubator to help the bacteria grow.
- Why: We did this experiment to really help us understand how important it is to have clean hands as a nurse and how important it is to thoroughly clean our hands. As nurses if our hands are not properly cleaned then we can transfer bacteria to patients and give them an infection.
Experiment 2: Preparing Culture Media
Materials:
- dehydrated medium
- balance
- weigh boats
- spatula
- distilled water
- large glass flask
- petri plates
What we did and why:
- What: We are learning how to prepare a culture media to grow bacteria on.
1. We measured 4.6g of the nutrient agar using a balance and a weigh boat.
2. We measured out 200mL of distilled water and poured it into a flask and then added the 4.6g of nutrient agar powder and mixed them together.
3. We put the nutrient agar solution into the Autoclave to sterilize it.The pressure in the autoclave increases the temperature.
4. We now let the solution cool to 35-40 degrees Celsius. Once it cooled down we poured the liquid nutrient agar into petri plates.
5. We let the nutrient agar cool so that it can solidify into a Jell-O-like consistency.
6. Ta-Da!!! Now we have 8 new nutrient agar plates!
Why: We needed to learn how to make media cultures so that we can properly grow bacteria.
Experiment 3: Aseptic Technique and Stab Technique
Materials:
- broth culture of bacteria
- sterile nutrient broth tube
- sterile nutrient agar slant
- sterile nutrient agar plate
- inoculating loops and needles
What we did and why:
What: We learned how to properly perform Asceptic Technique and Stab Technique
1. First we sterilized the inoculating loop by heating it with the Bunsen burner.
2. We sterilize the opening of the the bacterial broth tube using the Bunsen burner
3.Next we insert the sterile inoculating loop into the broth and put the lid back on.
4. Now sterilize the fresh broth tube and insert the inoculating loop and roll it between your fingers to dislodge the bacteria and put the lid back on.
For inoculating an agar slant using the aseptic technique: Steps 1-3 are the same
4. sterilize the opening of the agar slant
5. insert the loop and place it on the bottom of the slant and squiggle the loop back and forth up the entire slant and put the lid on.
Stab Technique: 1. Sterilize the inoculating needle.
2. Sterilize the bacterial broth and insert the inoculating needle.
3. sterilized the agar slant
4. stab the needle straight down the the agar slant and put the lid back on
Why: We did this so we could learn to inoculate culture media with a specific bacteria without introducing contaminating microbes. This technique is used to create an environment that is free of harmful microorganisms. Successful cell culture depends heavily on keeping the cells free from contamination by harmful microorganisms such as bacterial, fungi, and viruses.
Experiment 4: Environmental Sample
Materials:
- sterile swab
- clean agar plate
- environmental sample
What we did and Why:
What: We took a sample from the environment to grow bacteria from it.
1.We ventured out into the great unknown (our campus) to search for our environmental sample
2. We chose a clean plate from the cafeteria and swabbed it and brought the swab back to the lab.
3. Next we inoculated the agar plate and labeled it and placed it in the incubator.
The results will be posted in tomorrows lab.
Why: The purpose of this experiment was to become aware of all of the bacteria that is in the environment.
