Aseptic technique

Sterile technique is used to ensure a "clean" lab environment. It is essential to ensure the reliability of experimental results.

Sterile practices are especially important when working with microorganisms. A single spore or tiny bacterium can overgrow your whole medium and destroy your experiment.

The following steps are used to keep laboratory work sterile:

Laboratory doors and windows are kept closed to prevent air currents, preventing surface microorganisms becoming airborne.
The wire loop and glass spreader are sterilized before and after use with a Bunsen burner to prevent the introduction of unwanted microorganisms.
Lids from bottles and tubes are held when removed, and not placed on the bench during material transfer from one bottle or tube to another.
The neck of a bottle or tube must be immediately heated using the Bunsen burner so that any air movement is outward.
The bottle or tube are opened for the minimum time possible, and while open, all work is performed close to the Bunsen burner flame.
Media and equipment are sterilized to prevent the growth of unwanted microorganisms.

There are two images: on the left, a contaminated petri dish that contains two big fuzzy white fungal growths. On the right, a wire loop is being sterilized by placing it through the flame of a gas burner.

Figures 1: Left- A contaminated petri dish. Various species of fungi have grown in this petri dish. Image Source : Wikimedia Commons. Right- Sterile technique by sterilizing a wire loop through the flame of a gas burner. Image Source : Wikimedia Commons

Referred from:

Polymerase Chain Reaction Simulation