What’s the best way to not cut agar?
- Next time you have a few plates to streak, try holding your loop at a different angle for each plate so that you can figure out how to hold it without cutting the agar.
- 1 What is the correct way to open an agar plate when you want to inoculate the agar?
- 2 What is the purpose of Parafilming the plates?
- 3 How do you handle agar plates?
- 4 Why is agar plate upside down?
- 5 How do you correctly position a plate for storage?
- 6 Do I need to seal agar plates?
- 7 Why do we seal Petri dishes?
- 8 Why do you need to Sterilise Petri dishes and culture mediums before use?
- 9 How do you keep agar plates from drying out?
- 10 How do you stop condensation on agar plates?
- 11 How is streaking done?
- 12 How should agar plates be incubated Why?
- 13 What is an agar stab?
What is the correct way to open an agar plate when you want to inoculate the agar?
Uncover each agar plate just long enough to inoculate the medium. hold the petri dish lid directly over the petri dish (or tilt the lid just enough to allow the loop inside) while inoculating the medium to help prevent contamination from air-borne particles. Do not allow the loop to touch the petri dish.
What is the purpose of Parafilming the plates?
Parafilm is a flexible film, available in several different lengths and widths. It is commonly used for sealing or protecting containers, like our Petri dishes. It will help to ensure that our samples do not become contaminated by outside substances.
How do you handle agar plates?
How To Handle Microbiological Media (Agar Plates)
- Microbiological Media must be kept refrigerated or on ice until ready to use.
- The plates must be allowed to warm up to room temperature before taking a sample (approx.
- Do not remove the lid from the plate at any time except during sampling.
Why is agar plate upside down?
Petri dishes need to be incubated upside-down to lessen contamination risks from airborne particles landing on them and to prevent the accumulation of water condensation that could disturb or compromise a culture.
How do you correctly position a plate for storage?
Agar plates must be kept free of bacteria during storage. Store agar plates upside down. Stack the plates in their original bags for further protection from contamination.
Do I need to seal agar plates?
Yes, you really have to seal it with parafilm to prevent contamination especially when you incubate the plates, there is a very high chance of being contaminated without the parafilm. Only chances of contamination is may be handling or during work.
Why do we seal Petri dishes?
When growing bacteria, it is usual to invert the Petri dishes, so as to prevent condensation droplets from falling onto the surface of the agar. Petri dishes are often “sealed” at this stage to prevent people who handle them from contamination by bacteria, which will multiply greatly.
Why do you need to Sterilise Petri dishes and culture mediums before use?
Preparing the agar plates for growth of a colony of bacteria Glass petri dishes and agar gel must be sterilised before use by using an autoclave, or pre-sterilised plastic petri dishes can be bought. Reason – this will kill any unwanted bacteria that are present in the solution or on the petri dishes.
How do you keep agar plates from drying out?
Store plates upside down in a refrigerator or cold room. If they are stored in a room, check the plates after a few hours for condensation in the lid. If you have the plates upside down and there is condensation in the lid, there must be some heat source above that is driving water out of the agar and into the lid.
How do you stop condensation on agar plates?
A significant reduction in the amount of condensation can be achieved by allowing the sterilized agar to cool to 50°C–55°C before pouring. A water bath set at 50°C is useful to store bottles of molten agar to maintain the optimal temperature prior to pouring plates. Remember agar solidifies at around 42°C.
How is streaking done?
The streaking is done using a sterile tool, such as a cotton swab or commonly an inoculation loop. The inoculation loop is first sterilized by passing it through a flame. When the loop is cool, it is dipped into an inoculum such as a broth or patient specimen containing many species of bacteria.
How should agar plates be incubated Why?
Agar plates should be incubated in an inverted position to prevent condensation on the agar surface that could spread the inoculated organisms.
What is an agar stab?
A stab is a type of Luria Broth (LB) Agar media, similar to a standard LB Agar plate. Unlike an LB Agar plate, a stab culture is created by piercing the LB agar with the bacteria instead of spreading it on the surface. The bacteria in the stab is guaranteed to live for at least 2 weeks when stored at 4°C.