Why do you have to flame the loop before & after use?

Why do you have to flame the loop before & after use?

The most important tool for transferring cultures is the wire inoculating needle or loop. It can be quickly sterilized by heating it to red hot in a Bunsen burner flame. Always flame the loop immediately before and after use! Allow it to cool before picking up an inoculum of bacteria (or you will kill the bacteria).

Why do you flame the loop before placing it into the culture?

The flaming procedure should heat the tip of the loop gradually. This is because after use it will contain culture, which may splutter on rapid heating and possibly release small particles of culture, forming an aerosol.

Why are the agar plates incubated 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.

Why does a bottle need to be passed through a flame?

Passing the mouth of the bottle through a flame produces a convection current away from the opening, and helps to prevent contamination. The hot part of the flame is above the inner bright blue ‘cone’ and the vessel needs to be moved through the flame, not held in place.

Why should you flame the mouth of a test tube?

“Flaming the mouth of a test tube creates an air flow. Hot air rises. Therefore dust/particles in the air are less likely to fall into your tube. There is some controversy as to the value of this action. The hot air will also create eddy currents across the mouth of the tube or flask which may actually increase the opportunity for contamination.

Do you have to flame the lip of a culture tube?

Also, keep the lid over a plate when removing inoculum, as this will help prevent environmental contamination. Always flame the lip of a culture tube when you open it and before you replace the cap.

What’s the best way to clean a media bottle?

When using media in glass containers, run the mouth of the bottle through the flame of your bunsen burner before inserting a pipet and before replacing the lid. This helps to prevent contamination from the lip of the bottle.