Aseptic Technique and Bacterial Inoculation

Vocabulary terms and procedures related to laboratory aseptic techniques, sterilization of tools, and bacterial inoculation from culture plates to broth media.

Aseptic Technique

Practices and procedures that prevent contamination of cultures from foreign bacteria during culture transfer, media inoculation, pure culture isolation, or microbiological testing.

Flame sterilization

A sterilization method where an inoculating loop or needle is heated until it turns bright red in color to ensure it is sterile.

Bacti-cinerator

An electronic device used to heat an inoculating loop or needle until it is "flame-red" or "red hot" for sterilization.

Bunsen burner

A traditional heat sterilization tool that is no longer recommended because the gas used is highly explosive.

BSC (Biosafety Cabinet) Air Flow

A system where air is filtered before entering the workspace, moves upward to be filtered by a HEPA filter, with 70% of air recirculated and 30% exhausted.

HEPA filter

The specialized filter used in a biosafety cabinet to process the upward-moving air within the workspace.

Sterilization Angle

The approximately $60^{\circ}$ angle at which an inoculating loop or needle should be held just outside the blue cone of an alcohol lamp flame.

Loop Cooling Time

The mandatory period of 10-30 seconds to wait after sterilization before the loop touches microorganisms or media.

Hissing sound

An indicator that the inoculating loop was not cooled sufficiently, which may create aerosols upon contact with media containing microorganisms.

Last quadrant streak

The specific area on a culture plate from which a well-isolated colony should be selected for inoculation.

Tube mouth sterilization

The process of passing the opening of a test tube through a flame 2-3 times to prevent airborne contaminants from entering and to cause local air to rise.

Incubation Temperature

The specific temperature of $35^{\circ}C$ required for incubating the nutrient broth.

Incubation Duration

The required time frame of 18 to 24 hours for the growth of the bacterial culture.

Turbid

A visual characteristic of the nutrient broth that serves as a sign of bacterial colony growth.

Subculturing

The microbiological process of transferring microorganisms from a stock culture to a new medium.