Aseptic Technique Flashcards
What apparatus is needed in the aseptic technique to grow bacteria
Petri dish, warm fluid agar, sellotape, cotton buds, Bunsen burner, heatproof mat, safety glasses.
What is the method to use the aseptic technique to grow bacteria
Bunsen on heatproof mat.
Petri dish on mat close to Bunsen.
Using a chinagraph pencil draw a line down the middle of the dish on the outside base so have 2 different sides.
Carefully unscrew lid from the bottle of agar.
Flame mouth of bottle in blue Bunsen flame.
Lift lid of Petri dish to allow agar to be poured in.
Close lid quickly.
Gently move the dish so the base is completely covered in agar.
Let set for 5/10 minutes.
Use the cotton bud to obtain microbes from your chosen area.
Go to the Bunsen.
Lift the lid of the Petri dish beside the Bunsen and carefully stroke the cotton bud over the surface of the agar.(don’t damage the surface).
Put the lid on.
Seal with sellotape.
Put the date on the outside of the dish and write where you collected the microbes.
Place in the incubator upside down.
Where did you collect microbes and how did the Petri dish look after 2 weeks
Changing room floor, completely covered with microbes.
As bacteria grow rapidly…
Each individual microbe from your chosen source will divide again and again giving rise to a group of bacteria on the surface of the agar.
What do the bacteria colonies look like on the agar
Creamy white disks
What does the number of colonies on the agar tell you
How many bacteria you put on the agar. You may also see furry growth - these represent growth of fungi.
Where would bacteria probably grow easily
Humid and warm conditions.
Give an example of when aseptic technique may be used
Biologist, surgeon, doctors, chef, tattooist, dentist
Give me 3 measures that are taken when working under aseptic conditions
Work beside a Bunsen burner so the flame heat kills bacteria.
Clean surface.
Wash hands thoroughly.
Protective clothing e.g. lab coat , scrubs, gloves and dispose of these correctly.
Autoclave equipment.
Why is it recommended to work close to a Bunsen when making growth plates?
Convection current removes unwanted microorganisms in the air.
Why is it necessary to flame the neck of the bottle of agar
It destroys unwanted microbes on the glass bottle.
Why do you incubate the Petri dish upside down
It stops the agar during out and stops condensation from gathering on the lid and washing away bacterial colonies.
Why would it be dangerous to incubate the growth plates at 37 degrees
It’s body temperature so it would increase the likelihood of growing pathogenic microorganisms that could cause illness.
What does using the aseptic technique ensure
The bacteria you are looking at have come from one single source.
Where would an environmental health laboratory need to take bacterial samples
Restaurants where there is a case of food poisoning.
What is the aseptic technique
Involves the use of sterile equipment.
Much like that in operating theatres. Much of the equipment will be sterilised in an autoclave (a bit like a large pressure cooker).
In addition scientists must wear white coats in the lab to prevent microbes from their clothes contaminating the samples. The white coat will then be taken off before they leave the lab.
What is the special jelly used to grow bacteria called
Agar
Why and how is agar used
Agar contains all the necessary nutrients required for the bacteria to grow. It’s warmed to make it sterile then poured into a Petri dish. When working under aseptic conditions work close to a Bunsen. This creates a convection current to stop bacteria from the air falling into the sample.
What is microbiology
The study of microbes and microorganisms
Why do microbes matter
They affect every aspect of our lives. Understanding microbes help our health, environment, climate change, food , agriculture.
What are some careers where aseptic technique and microbiology are used regularly
Environmental health, dairy produce, agriculture, brewing, baking, medical research.
