Microbiology Lab Techniques and Historical Concepts

Flashcards covering microbiology laboratory streak plating procedures, slant cultures, and historical experiments in microbiology.

How many times should you take bacteria from the stock solution during a four-area streak plate procedure?

Only one time for Area 1.

Where should you cool down your loop after flaming it during a streak plate procedure?

In an area of the plate that does not have any agar or microbes.

Why is it important to close the agar plate lid between steps during a streak procedure?

To prevent contamination from unwanted microbes.

How should you flame the loop to ensure proper sterilization?

Flame the loop slowly from the bottom to the tip at the hottest area.

When taking a sample from a tube, how should you bring the sample onto the loop?

Move the tube towards the loop rather than moving the loop.

How many pieces of tape should be used to secure the plate, and where should they be placed?

Two little pieces of tape, placed in an area where nothing was written and no bacteria was applied.

How should the completed plate be positioned when placed in the bucket?

Facing up.

How does preparing a sample from an agar slant differ from preparing one from a liquid broth?

You do not need to agitate a slant to mix anything before taking a sample.

Why are agar slants prepared with a slanted surface?

To increase the surface area in order to grow more bacteria.

How does the bacterial concentration on an agar slant compare to that in a liquid broth?

The slant is much more concentrated with bacteria than the broth.

What is the central belief of spontaneous generation?

That life comes from a vital force in the air rather than pre-existing life.

What was the function of the S-shaped neck on the flask in the experiment testing spontaneous generation?

It allowed the air or vital force to enter while trapping airborne bacteria in the bend so they could not reach the broth.

What is the difference between pasteurization and sterilization?

Pasteurization heats a substance to kill only some organisms, whereas sterilization kills all living organisms.

What figure was referred to as the "mother's savior" in the context of disease prevention?

A scientist/doctor mentioned in the lecture who helped reduce maternal deaths from infectious disease.

How does the cowpox vaccine protect a person against smallpox?

Injecting part of the virus stimulates the body to produce antibodies against it so the person does not get as sick if infected later.

In what year did the scientist observe that a fungus secreted a substance that prevented S. aureus from growing around it?

In 1928.

What term was used to describe different variants within the same species of bacteria, such as E. coli strains?

Serotype.