Question

1. Briefly describe the aseptic technique used in lab to prevent contamination of cultures (tubes and plates).

True or False:

1. All extremophile bacteria are sensitive to UV irradiation.

2. Deinococcus radiodurans have multiple genome copies and very efficient UV repair systems.

3. The purpose of endospores is to allow bacterial reproduction.

4. The decolorizer agent in the endospore stain is water.

Answer 1

1) Microbiologists use various aseptic techniques during lab procedures to prevent contamination. aseptic technique can minimize or may  eliminate the risk of contamination. Apart of this, aseptic technique is also importance in maintaining pure stock cultures during  transferring cultures to new media. Aseptic techniques commonly used in lab are.

1) sterile handle- this includes wipe of working area and hands by 70 percent alcohol.

Wear gloves during handling media to prevent contamination from touch.

To avoid cross contamination, use single time use disposable pipette to work with liquid.

Use steril glassware and instruments

2) inoculating agarcplates and culture

Carry culture media with short exposure to sir as quick as possible.

Always open petri plate away from the body and near to brunsen burner to prevent contamination.

3) use a wire loop

Heat the wire loop to red hot in to a bunsen burner which makes it sterile thus prevent contamination during the inoculation.

Use proper position of wire loop during working

Resterlize it after use.

4) use of pipette

Always use pipette during transfer of culture in to culture plates .

Use disposable pipettes tips.

5) flame the neck of the bottle and test tube.

Flaming of the mouth of culture bottle ensures that no microorganisms enter in to the vessel through the mouth to contaminate.

True and False

1. All extremophile bacteria are sensitive to UV irradiation.-- False

2. Deinococcus radiodurans have multiple genome copies and very efficient UV repair systems.-- True

3. The purpose of endospores is to allow bacterial reproduction.-- False

Primary function of endospore is to help in survival of bacteria in extreme conditions

4. The decolorizer agent in the endospore stain is water-- True