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What are the 6 I's that microbiologists use?

Inoculation, incubation, isolation, inspection, information gathering, and identification.

What is staining?

Staining is using dyes to add contrast so microorganisms and their structures can be seen more easily.

What is the overall charge of a bacterial cell?

Negative.

What are the 2 types of dyes?

Basic dyes and acidic dyes.

What is the charge of a basic dye and what does it stain?

A basic dye is positively charged and stains the negatively charged bacterial cell.

What is the charge of an acidic dye and what does it stain?

An acidic dye is negatively charged and stains the background because it is repelled by the negatively charged bacterial cell.

What is the difference between a positive and negative stain?

A positive stain colors the microorganism, while a negative stain colors the background.

Which dye is usually used for a positive stain?

A basic dye.

Which dye is usually used for a negative stain?

An acidic dye.

What does the simple stain show?

It shows the size, shape, and arrangement of bacterial cells.

How many dyes are used in a simple stain?

One dye.

What kind of dye is usually used in a simple stain?

A basic dye.

What do differential stains show?

They show differences between different types of microorganisms or cell structures.

How many dyes are used in differential stains?

Two or more dyes.

What kind of dyes are usually used in differential stains?

Usually basic dyes.

What are 3 examples of differential stains?

Gram stain, acid

Does the Gram stain pertain to charge?

No.

What color does a Gram

negative bacterium stain?

What color does a Gram

positive bacterium stain?

What are the primary and counterstains used in the Gram stain?

Primary stain

What are the primary and counterstains used in the acid

fast stain?

What are the primary and counterstains used in the endospore stain?

Primary stain

What color is an acid

fast positive bacterium?

What color is an acid

fast negative bacterium?

What color does an endospore stain?

Green.

What color does the vegetative cell stain in an endospore stain?

Red or pink.

What kind of stain is used to see a capsule?

A capsule stain or special structural stain.

Is media sterile?

Yes, culture media must be sterile before it is inoculated.

What is the difference between a mixed and pure culture?

A mixed culture contains more than one type of microorganism, while a pure culture contains only one type.

What temperature are our incubators set at?

37°C.

To what level do we want to identify microbes in the lab setting?

To the species level.

What are the 2 ways that taxonomists identify and classify microorganisms?

They use phenotypic characteristics and genotypic or molecular characteristics.

What is a culture medium?

A prepared material that provides microorganisms with the nutrients and conditions needed for growth.

In what 2 ways can media be classified?

By physical form and functional type.

What are the 3 physical forms of media?

Liquid, semisolid, and solid.

What is liquid media?

Media that does not contain enough solidifying agent to become solid; an example is broth.

What is semisolid media?

Media with a small amount of solidifying agent that gives it a soft consistency; it can be used for testing motility.

What is solid media?

Media containing enough agar to become solid; it is commonly used to grow colonies.

What is agar?

A polysaccharide from red algae that is used as a solidifying agent in culture media.

Who should be credited with the first use of agar in the microbiology lab?

Fanny Hesse.

What are the 4 functional types of media?

General

What is general

purpose media?

What is enriched media?

Media containing extra nutrients that support microorganisms with more demanding nutritional needs.

What is selective media?

Media that encourages the growth of certain microorganisms while inhibiting others.

What is differential media?

Media that allows microorganisms to grow but provides a visible way to distinguish between them.

How can media be selective and differential?

It can inhibit certain organisms while allowing others to grow and then show visible differences between the organisms that grow.

What is an example of selective and differential media?

Mannitol salt agar is selective because high salt inhibits many bacteria and differential because it shows whether bacteria ferment mannitol.

How can media be enriched and differential?

It can contain extra nutrients for fastidious organisms while also showing visible differences between organisms.

What is an example of enriched and differential media?

Blood agar is enriched because it supports fastidious organisms and differential because it shows different hemolysis patterns.

How high can a light microscope magnify?

A light microscope can magnify up to about 1,000–2,000 times depending on the microscope.

How high can our scopes go?

The laboratory compound microscopes can reach about 1,000X total magnification using the 100X oil

What objective is used in the lab to best see microbes?

The 100X oil

What are the microscope objectives and their magnifications?

Scanning objective

What is the ocular magnification?

Usually 10X.

How do you calculate total magnification?

Objective magnification × ocular magnification.

What is the total magnification with the 4X objective?

40X.

What is the total magnification with the 10X objective?

100X.

What is the total magnification with the 40X objective?

400X.

What is the total magnification with the 100X objective?

1,000X.