In this video, you will learn the proper practices and procedures for performing aseptic technique. Using aseptic technique, you will be able to transfer a bacterial monoculture into a fresh medium without introducing any contaminating microorganisms. Two of the most commonly used tools for transferring bacteria are the inoculation loop and the inoculation needle.
Knowing how to use a Bunsen burner is an important skill in aseptic technique. To light a Bunsen burner, start by closing the valve at the base by rotating the collar so that the vents are covered. Then slowly turn on the gas. Once you hear the gas, ignite the burner and set the height of the flame by adjusting the amount of gas. The temperature of the flame can be adjusted by rotating the collar to control the flow of oxygen.
The coolest flame is yellow and orange. A medium flame is blue. And the hottest flame is a roaring blue flame characterized by a clear blue cone in the middle.
The tip of the cone is the hottest part of the flame. Inoculation tools are sterilized by passing them through the hottest part of the flame. Once sterilized, inoculation tools should not be set down on any surface. In this section you will learn how to transfer bacteria from a liquid culture to a petri dish.
After flaming a loop, take the lid off the container of liquid culture and pass the mouth through the flame. Then dip the loop into the liquid culture and flame the mouth again before replacing the lid. Transfer the bacteria to your petri plate.
Lift the lid of the plate and hold it over the base as a shield. to prevent contaminants from falling onto the plate. Spread the bacteria over the entire surface of the plate in all directions.
Rotating the plate a quarter turn between spreads will ensure that the bacteria is spread evenly across the plate. In this section you will learn how to transfer bacteria from a liquid culture to a liquid. After sterilizing an inoculation loop, take the lid off the container of liquid culture and pass the mouth through the flame.
Then dip the loop into the liquid culture and flame the mouth again before replacing the lid. Now take the tube of liquid media and pass the mouth through the flame. Then dip the loop with bacteria into the tube.
Flame the mouth of the tube before replacing the lid. Flame the loop to sterilize. In this section you will learn how to transfer bacteria from a petri plate to a stab culture.
Start by sterilizing an inoculation needle by passing it through a flame. Allow the needle to cool. You can test for coolness by tapping the needle in a clear area on your auger plate.
While holding the lid as a shield, gently rub the inoculation needle over a single colony. Transfer the bacteria to a culture tube filled with nutrient auger. Remove the top of the tube and insert the needle, making three deep stabs.
When finished, replace the lid on the tube and sterilize the needle. In this section you will learn how to transfer bacteria from a petri plate to a liquid. Sterilize an inoculation loop by passing it through a flame.
Let the loop cool. You can test for coolness by tapping the loop in a clear area on your auger plate. While holding the lid as a shield, gently rub the inoculation loop over a single colony.
Now take the tube of liquid media, remove the lid, and pass the mouth through the flame. Then dip the loop with bacteria into the tube. Pass the mouth of the container through the flame before replacing the lid. Sterilize the inoculation loop to complete the process.