Aseptic Techniques and Tools in Microbiology: Inoculating Loops, Sterilization, and Pure Cultures

Aseptic techniques

Prevent introducing or spreading unwanted microbes.

Inoculating loop

Made of Nichrome wire with an insulated handle.

Flame the inoculating loop

Flame until red-hot before and after every use.

Sterilization methods for inoculating loop

Hold wire at the edge of the inner blue flame or sterilize in an electric incinerator.

Single-use plastic loops

Never heat, remove aseptically from packaging.

Transfers using inoculating loop

Use the inoculating loop to transfer bacteria between media and onto slides.

Cooling the loop

Let the loop cool briefly after flaming before touching your culture.

Pure cultures

One species only; any contamination ruins it.

Role of aseptic technique

Aseptic technique is what makes pure cultures possible.