Admin Table of Contents
- 1 Why are plated media stored in an inverted position?
- 2 Why is it important to invert the petri plates during incubation?
- 3 How long are inoculated petri plates incubated until they are discarded?
- 4 Why is it necessary to sterilize the loop between streaks when streaking for single colonies?
- 5 Why should open cuts be covered before working with microorganisms quizlet?
- 6 How do you dispose of agar plates?
Why are plated media stored in an inverted position?
Plates should be stored in the inverted position to prevent moisture from contacting the surface of the media. Media should never be exposed to sunlight or UV light, since many ingredients, especially dyes and indicators, are not stable upon light or heat exposure.
Why is it important to invert the petri plates during incubation?
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.
Why should a petri dish not be left open for any extended period?
Petri dishes should not be kept open to reduce the risk of contamination by air microbes. Cross contamination can occur as a result. If a petri plate becomes contaminated by microbes, it will interfere with the growth of the target microbes within the plates, and it will hamper the cell culture process.
Can you store the media in petri plates at room temperature?
Temperature and time Culture Media: Sealed, unopened containers should be stored at room temperature 15-20°C. Opened containers should have the cap or lid carefully and securely replaced. It is important that opened containers are stored in a dry atmosphere at room temperature. Shelf life 1 to 5 years.
How long are inoculated petri plates incubated until they are discarded?
30 min
Cells are incubated in these dishes for 30 min at 37°C.
Why is it necessary to sterilize the loop between streaks when streaking for single colonies?
Don’t forget to sterilize. Flame the loop or use a new disposable loop after you streak each quadrant. Using a new or sterilized loop allows you to effectively dilute the inoculum on the plate and obtain isolated colonies by spreading the inoculum thinner and more evenly.
Why should you avoid pressing the toothpick into the agar?
Disposable pre-sterilized sticks and toothpicks need not be flamed with the Bunsen burner thus preventing unnecessary aerosolization of spore-forming bacteria and cross-contamination of laboratory surfaces or agar plates with spores.
Why is it important to limit the duration that cultures media and petri dishes are left open?
limiting the duration that cultures or media are uncapped and exposed to the air. effectively sterilizing inoculating loops and other equipment that comes into contact with cultures or media, and. avoiding breathing on cultures or sterile instruments.
Why should open cuts be covered before working with microorganisms quizlet?
Why should open cuts be covered before working with microorganisms? Because the microbes used in this lab are opportunists, you must cover all fresh skin wounds before coming to lab. Do not bring food, drinks, or use cosmetics in the lab.
How do you dispose of agar plates?
Dispose of unused plain agar in plastic plates directly into a trash can. Agar with any additives are biohazards and should be sterilized before disposal. Scrape unused agar out of glass petri dishes and throw it away. Wash and reuse glass plates.
Why is it important to pour plates before the agar starts to solidify?
If 35 g of LB agar powder is required to make 1L of LB agar, how much LB agar powder is needed to make 100ml of LB agar? Why is it important to pour plates before the agar starts solidify? So the surface of your plate is nice and smooth. Why is it important to cool agar prior to adding ampicillin?