Microbio E1 Ch3

Know the basics of culturing organisms

Microbiologists use several techniques to manipulate, grow, examine and characterize microorganisms in the laboratory

What are the 5 I's

inoculation, incubation, isolation, inspection, identification

What is inoculation?

adding small sample (the inoculum) into a container of medium

What is incubation?

When the sample is kept between 20 degrees Celsius and 40 degrees Celsius to allow growth

What is a pure culture?

growth of only a single known species

What is a mixed culture?

culture consisting of two or more species

What is selective media

contains one or more agents that inhibit growth of some microbes and encourage growth of the desired/certain microbes, but not others

What is differential media?

Allows growth of several types of microbes and displays visible differences among those microbes

What is enriched media?

Contains complex organic substances(growth factors) to support growth of fastidious bacteria

What are growth factors?

Proteins released by other cells that stimulate cells to divide.

What is a fastidious bacteria?

An organism that has complex or particular nutritional requirements

What is resolution?

The ability to distinguish two adjacent objects or points from one another

What is the field of view?

the area that the eyes can perceive without moving the eyes or head.

What is magnification?

the increase in the apparent size of an object

What is a wet mount?

Cells suspended In a fluid, a drop or two of the culture is then placed on a slide and over laid with a cover glass

What is total magnification?

objective lens x ocular lens

What is a simple stain?

Require on a single dye

What is differential staining

Use two differently colored dyes, called the primary dye and the counter stain, to distinguish between cells types or parts which Include; gram, acid fast, and endospore

What is gram staining

The most universal diagnostic staining technique: differentiation of microbes as gram positive(purple) or gram negative(red)

What is acid-fast staining

Like the gram stain, it's an important diagnostic stain that differentiates acid-fast bacteria(pink or red) from non acid-fast bacteria(blue) :important in medical biology and originated as a specific method to detect mycobacterium

What is endospore

A dye is forced by heat into impermeable/ resistant bodies called endospores :distinguishes between endospores and the cells that they come from

Streak plate

small droplet of culture or sample spread surface of medium with an inoculating loop

Loop dilation method

Sample inoculated serially in to a series of liquid agar tubes to dilute the number of cells in successive tubes

spread plate method

small volume of liquid, diluted sample pipette on to surface of the medium and spread around evenly by a sterile spreading tool