Aseptic Transfer Technique - Methods and Precautions

Introduction about Aseptic Transfer Technique

Aseptic Transfer Technique a simple technique that used to minimize the risk of culture contamination (and the risk of making oneself sick).

In our local environments, microorganisms are ubiquitous. They are in the air, on our skin, on the bench top, and on every other surface.
This is problematic when working in a microbiology lab because we generally want to work with pure cultures (cultures that contain one and only one species of microorganism).

When culturing microbes, we must assume that everything (except the inside of sterile culture media) is contaminated.
In order to transfer cells to new cultures, we must make sure that we sterilize everything that can potentially contaminate the cultures.

Who discovered Aseptic Transfer Technique?

In the mid-1800s, Louis Pasteur developed the techniques of aseptic transfer to minimize the risk of culture contamination (and the risk of making oneself sick). In today’s lab we will learn the steps in aseptic transfer.

Points should be remembered during aseptic handling

The lab should be maintained in a clean and dust-free condition. Coughing, sneezing, and talking while working should be avoided.
The stoppers, plugs of culture containers should be tightly plugged. The culture containers should be opened only for short time.
The plugs should not be placed on the working tables.

If pipettes are to be used they should unwrapped only before use with the tip in the aseptic zone.
If wire loop is to be used, it should be sterilized by directly heating until it becomes red hot.
It should be allowed to cool sufficiently before using it for any aseptic work.

If sterile liquid is to be poured from one sterile container to other the mouth of both the containers should be flamed.

Materials Used

A bacterial culture suspension
Wire-loop

Nutrient medium containing tube or Petri plate

Method of Aseptic Transfer Technique

Loosen, but don’t remove the cotton plug on the tube. Hold the inoculating loop at the end of the rubber/plastic portion of the handle.
Stick the loop into the flame until it becomes RED HOT. Flame the entire wire loop and about half of the metal portion of the handle (because part of the metal portion will extend into the test tubes).

Remove the caps and hold them in the same hand as the loop.

Where could aseptic technique used for?

In operation theater we should be very clean and starile. We should use aseptic transfer technique during such a sensitive phase.

Handling surgery equipment in operation theater.

Helping with a baby’s birth by vaginal during birth delivery.
Handling dialysis catheters.
Performing dialysis.

Inserting a chest tube.
Inserting a urinary catheter.
Inserting central intravenous (IV) or arterial lines.

Inserting other draining devices.

Precaution during Aseptic Transfer Technique

To avoid contamination of the cotton plugs: don’t set them down on the bench top; don’t touch the cotton plug at the bottom (that enters the tube)
Flame the mouths of the test tubes. The mouths may be contaminated. We don’t want to drag the loop across the mouth of a tube and contaminate our culture.

Cool the loop by tapping it on the sterile agar or in the sterile broth.
Insert the loop into the stock culture to obtain [a small amount of] cells. You don’t need to see cells on the loop to have enough.
Take out the wire loop and reset the cotton plug in the tube.

Re-flame the mouths of the tube. Then put the caps back on. Keep tube in test tube holder.
Take the medium containing tube to which the culture has to be transferred.
Immediately transfer cells to the sterile medium.

This should be very quick

Remove the cotton plug and flame the mouths of the test tubes.
Insert the loop into the medium and mix the culture in it.
Take out the wire loop; re-flame it and reset the cotton plug in the tube.

Incubate the tube under appropriate conditions and record the results.

References

FAQs : Aseptic Transfer Technique

1. What are the steps of aseptic technique?

Ans :
Loosen, but don’t remove the cotton plug on the tube.
Hold the inoculating loop at the end of the rubber/plastic portion of the handle.
Stick the loop into the flame until it becomes RED HOT.
Flame the entire wire loop and about half of the metal portion of the handle (because part of the metal portion will extend into the test tubes).
Remove the caps and hold them in the same hand as the loop.

2. What are 5 aseptic techniques?

Ans : Cotten Plug – Don’t remove the cotton plug on the tube.
Inoculating Loop – Hold the inoculating loop at the end of the rubber/plastic portion of the handle.
Flaming – Stick the loop into the flame until it becomes RED HOT.
Flaming Wire Loop – Flame the entire wire loop and about half of the metal portion of the handle.
Remove the caps and hold them in the same hand as the loop.

3. Who discovered aseptic transfer technique?

Ans : Louis Pasteur developed the techniques of aseptic transfer to minimize the risk of culture contamination.

Aseptic Transfer Technique – Methods and Precautions | Biology Ideas