Chapter 2 Handout

What are the major characteristics of light microscopy

uses light waves, glass lenses, and resolution is .2 micrometers

what are the major terms used in electron microscopy

electron waves, electromagnetic lenses, resolution limit is typically .23 micrometers

what are the types of light microscopes

compound

bright field

dark field

phase contrast

fluorescence

confocal

inverted

what are the types of electron microscopes

transmission electron

scanning electron

cryo-electron

scanning probe

what are the steps of light microscopy preparation

fixation, staining

what is simple staining

a single stain is used to determine size, shape, arrangement of bacteria

what are the types of simple stains

crystal violet, methylene blue, safranin, malachite green,

what is differential staining

helps divide organisms into groups based on staining properties. detect presence or absence of structures

what are types of differential stains

gram stain

acid fast stain

what is negative staining

produces images bright against a dark background

what is shadowing

specimen is coated with a heavy metal

freeze etching

samples are rapidly frozen in liquid nitrogen

what are characteristics of scanning probe microscopy

measures surface features of an object by moving a sharp probe over an objects surface

what are the types of scanning probe microscopy

scanning tunneling

atomic force

compound light microscope

A microscope that uses multiple lenses to magnify small objects. It uses a combination of lenses, including an objective lens and an eyepiece lens, to produce a magnified image.

bright field microscope

Microscope that uses a bright light source to illuminate the specimen. Produces a dark image against a bright background. Commonly used in biology and medical labs for observing stained samples.

dark field microscope

contains a special condenser that scatters light and causes it to reflect off the specimen at an angle

phase contrast microscope

Microscope technique that enhances contrast in transparent specimens by exploiting differences in refractive index. Achieved by using a special condenser and objective lens to create a phase shift in the light passing through the specimen. Allows for visualization of transparent samples without the need for staining or fixing.

fluorescence

Process where a substance absorbs light at one wavelength and emits light at a longer wavelength. Commonly used in microscopy and bioimaging techniques.

confocal

A microscopy technique that uses a pinhole to eliminate out-of-focus light, resulting in high-resolution images with improved optical sectioning.

inverted microscope

A microscope where the objective lens is positioned below the specimen, allowing for the observation of cells or other samples in a culture dish or container.

transmission electron microscope

Uses a beam of electrons to visualize the ultrastructure of specimens. Provides high-resolution images of internal structures and surfaces.

scanning electron microscope

Uses a beam of electrons to create high-resolution images of the surface of a sample. Provides detailed information about the sample's topography, composition, and morphology.

cryo electron microscope

A powerful microscope that uses beams of electrons to visualize the structure of frozen samples at a high resolution.

scanning probe

A type of microscope that uses a physical probe to scan and create images of a sample's surface at the nanoscale. It can provide high-resolution images and gather information about the sample's properties, such as topography, conductivity, and magnetic fields.