Aseptic technique Flashcards
Were all your transfers successful?
How do you know your transfer to a broth was successful?
How do you know your transfers to agar slants were successful?
Success is presence of growth
If any of your transfers were unsuccessful, suggest possible errors that may have been made in the transfer process
Failure is no growth;or growth of a wide variety of colonies, contamination
Provide three reasons why the use of aseptic technique is essential when handling microbial cultures in the laboratory
When handling microbial cultures, aseptic technique limits containation of yours and your workspace with the microbes in the cultures, and it limits contamination of your cultures with unwanted environmental microbes
Provide two examples of how heat is used during inoculation of a tube culture
The flame from a Bunsen burner is used to sterilize transfer instruments (e.g., inoculation loop) and is used to flame the opening of the tube after the cap is removed and before the cap is replaced
How is air contamination prevented when an inoculating loop is used to introduce or take a bacterial sample to/from an agar plate
Since the opening of a plate is not readily flamed, one should hold the lid over the top of the open plate when inoculating so that air contamination is limited. Working near a flame is also useful
Where should a label be written on an agar plate
Labels should be written on the bottom of the agar plate
How should agar plates be incubated? Why?
Agar plates should be incubated in an inverted position to prevent condensation on the agar surface that would spread the inoculated organisms
Disinfectants are effective against which types of organisms? Which types of organisms may remain on the lab bench even after disinfection? What disinfectants is used in your laboratory
Disinfectants, such a bleach and alcohol, are generally useful against vegetative cell and viruses but may not completely eradicate bacterial endospores
Compare and contrast the growth of bacteria in different physical types of media (broths, slants, and agar plates). What might be the advantages and disadvantages of using each type
The presence of growth in a liquid media such as a broth is indicated by turbidity or cloudiness. Individual colonies are not visible and one species could not be separated from another. Solid media such as slants allow for visible growth on the surface that can be observed for color and texture, etc. Plates allow for isolated colony
A disinfectant is used on your work surface
(A) before the beginning of laboratory procedures
(B) after all work is complete
(C) after any spill of live microorganisms
To retrieve a simple from a culture tube with an incoulating loop, the cap of the tube is
Removed and held with the fingers of the loop hand
An inoculating loop or needle is sterilized using heat
Until the entire wire is bright red
Which of the following world be a correctly labeled agar plate?
S. aureus on the bottom
Noah wanted to transfer Staphylococcus aureus from a broth to an agar plate. He picked up the broth culture, removed the cap, and flamed the mouth of the tube. He inserted an inoculating loop to obtain a bacterial sample. Then he flamed the mouth of the tube and replaced the cap. Noah opened the lid of a labeled agar plate diagonally and used the loop to streak the surface of the agar. After closing the lid, he flamed the loop in an incinerator and put it back in its container. The plate was incubated upside down for 24-48 hours. What did Noah do wrong in this transfer
He did not use the transfer tool correctly