Chapter 3

Resolution

________: ability to distinguish two adjacent objects or points from one another.

Isolation

________: Separating species in a culture.

Inspection

________ and Identification: using appearance as well as metabolism (biochemical tests) and sometimes genetic analysis or immunologic testing to identify the organisms in a culture.

Incubation

________: usually around 20- 40 Celsius; can control atmosphere as well.

Transmission

________ electron microscope: Electrons transmitted through specimen; the dark areas represent denser areas.

Vaseline

Hanging drop mount: uses depression slide, ________, and coverslip; the sample is suspended from the coverslip.

Smear technique

________: spread thin film made from liquid suspension of cell and airdrying it; heat fixate.

Inoculation

________: producing a culture.

Positive staining

________: dye sticks to specimen to give color.

Streak Plate Method

________: small droplet of culture or sample spread over surface of the medium with an inoculating loop.

Magnification

________: An image is formed by the refracted light when an object is placed a certain distance from the lens and is illuminated with light.

Enumeration media

________: count number of organisms in sample.

Pure culture

________ (axenic): growth of only a single known species.

Special Stains

________: Used to emphasize certain parts are that arent emphasized certain cell parts that arent revealed by conventional staining.

Negative Staining

________: dye does not stick to specimen and settles around the boundaries; india ink.

Confocal Microscopy

________: Uses a laser beam of light to view cells at higher magnifications and creates 3D model.

Resolving power equation

wavelength of light in nanometers /2 times objective lens.

Transport Media

________: used to maintain and preserve specimens.

Semisolid media

________: clot- like consistency at room temp.; determine motility and localize reactions.

Magnification

________ occurs in two phases: objective lens forms the real image and ocular lens forms the virtual image which equals the total power.

The 3 Classifications of Media

physical state, chemical composition, functional type

Liquid Media

water-based solutions that do not solidify above freezing; broths; Bacteria growth is seem as cloudiness/particles

Semisolid media

clot-like consistency at room temp.; determine motility and localize reactions

Solid media

a firm surface on which cells can form discrete colonies; a firm surface on which cells can form discrete colonies

Synthetic Media and example

compositions are precisely chemically defined; Glucose Salt Mediums

Complex (non-synthetic) media and examples

not chemically defined; nutrient broth, yeast extract broth, glucose broth

General purpose media and examples

to grow as broad a spectrum of microbes; usually non-synthetic; nutrient agar and broth, TSA

Enriched media and examples

contain complex organic substances to support fastidious bacteria; blood agar, thayer-martin medium

Selective media and examples

contains one or more agents that inhibit the growth of certain microbes; MSA, MacConkey agar

Differential media and example

allow multiple types of microorganisms to grow but display visible differences; MacConkey agar

Reducing Media

absorbs oxygen or slows its penetration in the medium; used for growing anaerobes or for determining oxygen requirements

Carbohydrate fermentation media

contain sugars that can be fermented and a pH indicator

Transport Media

used to maintain and preserve specimens

Assay Media

test effectiveness of antibiotics, antiseptics, etc

Enumeration media

count number of organisms in sample

The Five Is of Culturing Microbes

inoculation, incubation, isolation, inspection, identification

Inoculation

producing a culture

Isolation

Separating species in a culture

Streak Plate Method

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

Loop dilation/pour plate method

sample inoculated serially in to a series of liquid agar tubes to dilute the number of cells in each 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

Incubation

usually around 20-40 Celsius; can control atmosphere as well

Pure culture (axenic)

growth of only a single known species

Mixed culture

holds two or more identified species

Inspection and Identification

using appearance as well as metabolism (biochemical tests) and sometimes genetic analysis or immunologic testing to identify the organisms in a culture

Magnification

An image is formed by the refracted light when an object is placed a certain distance from the lens and is illuminated with light

The image is enlarged to a particular degree

the power of magnification

Magnification occurs in two phases

objective lens forms the real image and ocular lens forms the virtual image which equals the total power

Resolution

ability to distinguish two adjacent objects or points from one another

Resolving power equation

wavelength of light in nanometers/ 2 times objective lens

Shorter wavelengths of light equal

better resolution

Increased magnification decreases

the resolution

Visible light microscopes

bright-field, dark-field, phase contrast, and interference

Other light microscopes

Fluorescence microscopes and confocal microscopes

Phase-contrast microscope

allows differentiations of internal components of live unstained cells

Fluorescence Microscopes are commonly used to

diagnose infections caused by microbes using fluorescent antibodies

Confocal Microscopy

Uses a laser beam of light to view cells at higher magnifications and creates 3D model

Electron Microscopy

forms an image with a beam of electrons; increased resolving power and magnification

Transmission electron microscope

Electrons transmitted through specimen; the dark areas represent denser areas

Scanning Electron Microscope

Creates 3D view; Electrons bombard the surface of metal coated specimen

Hanging drop mount

uses depression slide, Vaseline, and coverslip; the sample is suspended from the coverslip

Smear technique

spread thin film made from liquid suspension of cell and airdrying it; heat fixate

Positive staining

dye sticks to specimen to give color

Negative Staining

dye does not stick to specimen and settles around the boundaries; india ink

Simple stain

require only dingle dye

Differential stains

use two different color dyes; primary dye and counter stain

Gram-staining

differentiates gram-positive and gram-negative bacteria

Acid-fast staining

differentiates acid-fast bacteria (pink) and non-acid fast (blue); diagnoses TB and leprosy

Endospore Stain

dye is forced into endospores by heat

Special Stains

Used to emphasize certain parts are that arent emphasized certain cell parts that arent revealed by conventional staining