Microscopy terms L1 Micro

Five Is

Inoculation (add small sample to medium) Incubation (provide the correct environment) Isolation (grow alone to make sure it is identifiable) Inspection Identification

Incubation

kept between 20-40 celsius

pure culture/Axenic

has only one species

Mixed Culture

has two or more identified species

Contaminated culture

has unwanted microorganisms of uncertainty

Inoculation

adding a small amount of a microorganism to a sample or person to allow it to grow

Pour plate vs spread plate

pour plate has colonies throughout the medium while spread plate is only at the surface of the medium

Defined media

The chemical composition of the media is precisely known

Complex media

one or more components is not chemically definable

General purpose media

grown to hold a wide range of microbes possible/ usually non synthetic/ contains a mixture of nutrients to support a wide range of microbes

Enriched media

Contains complex organic substances(growth factors) and support picky(fastidious bacteria)

Selective media

lets some organisms grow, but not others

Differential media

allow many microorganisms to grow but display visible differences (usually colors)

Inspection and Identification

using appearance as well as metabolism and sometimes genetics analysis or immunological testing to identify

How small can human eyes see

can see up to .2mm

wave length

shorter faster blue is more energy opposite is less energy

Refraction

when a photon changes speed and angle when passing through an object

Resolution

ability of a lens to distinguish detail and structure/ improve by increasing the numerical aperture or decreasing the wavelength of light ie. blue light

Numerical aperture

how well the lens gathers light

Resolving power = wavelength of light in nm / 2x numerical aperture

Lens system

ocular and objective lenses

Light source

visible light
(power of ocular lens)X(power of obj lens)

Fluorescence microscopy

uses ultra violet light source/ specimens that florence may release another color/ use antibodies with fluorescent dyes

Confocal microscopy

similar to fluorescence microscopy where they are stained with fluorochromes and uses laser light sources and computers slices and small pictures that are put together to make a single picture

TEM

highest magnification possible through electron beam allows you to see internal structures

SEM

allows you to see external structures and uses electron beam

Smear

thin layer of cells on a slide

Fixation

A method to kill and stick cells to a slide. most common way of fixation is with air or heat fixing

Stains

adds color to specimens/ made of salts and has positive and negative ions/

Chromophore

colored ion

Acidic dyes

binds to negatively charged surfaces repelled by bacterial surface/ chromophore is negative here/ ex. Nigrosin

Basic dyes

binds to negatively charged surfaces/ the chromophore is positively charged. / ex. Methylene Blue, Crystal Violet

Simple stain

Uses one dye or one step only/ may include a Mordant

Mordant

increases the interaction between the stain and the specimen

Differential stain

uses 1 dye and has several staining steps/ may include mordant/ can be used to distinguish between types of cells or structures

Gram stain

A differential stain that is the most important stain in bacteriology/It reacts with the cell wall components and reacts to positive and negative variants of cell walls