Why is it important to keep the petri dishes covered?

Why is it important to keep the petri dishes covered?

Prepared petri dishes should be refrigerated until used and always stored upside down (i.e media in upper dish, cover on bottom). This keeps condensation which forms in the lid from dropping onto and disrupting the bacteria growing surface.

Why is it important to keep the petri dish closed after inoculation?

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.

Should petri dishes be incubated with the lid side up?

Use of a paper towel to turn off a faucet. Use of a paper towel to turn off a faucet. Petri dishes should be incubated with the lid side up.

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.

Why does the lid of the agar plate have to be removed quizlet?

In order to sample the air for microbes, we are exposing our agar and TSA plates to the air by taking the lids off and then capping them after the assigned amount of time. TSA is a great medium to grow most bacteria but may not contain the required nutrients to sustain other living microorganisms in the air.

Why is it important to close the lid of the Petri dish immediately after transferring the bacterial sample to the medium?

The most exasperating problem confronting attempts to cultivate moulds is contamination by other moulds. Most mould spores are very light and easily transported by air. Even opening the lid of a Petri dish for a few seconds may allow the entry of contaminating organisms.

Do you think you should remove the cover of the Petri dish when exposing the bacteria to the UV light Why or why not?

1. The directions are not clear and do not mention removing the cover from the Petri dish. However, since plastics can block or scatter some UV rays, it would be better to remove it for the experiment.

What happens if you incubate bacteria too long?

If a bacterial culture is left in the same media for too long, the cells use up the available nutrients, excrete toxic metabolites, and eventually the entire population will die. Thus bacterial cultures must be periodically transferred, or subcultured, to new media to keep the bacterial population growing.

Why is it important that the petri plates are incubated upside down quizlet?

After the culture medium is set, and streaked with the required microbe/stock, the lid is put on and the petri dish is incubated upside down to minimize contamination. So, it is easier to read the label on the bottom. Also, if the lids are accidentally exchanged, it will be less of a problem.

Why is it important to close the lid of the petri dish immediately after transferring the bacterial sample to the medium?

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.