Viewing the Microbial World 2

Flashcards covering key vocabulary and concepts related to the microbial world, microscopy, and staining techniques.

Microbes

Microscopic entities requiring microscopes for observation.

Metric Units

Units used to express the sizes of microbes.

Micrometer (μm)

Unit of measurement for bacteria and protozoa sizes.

Nanometers (nm)

Term to measure sizes of microbes using the metric system.

Microscope

An optical instrument to observe small objects.

Resolving Power/Resolution

The limit of what can be seen with a microscope.

Simple Microscope

A microscope with only one magnifying lens.

Compound Microscope

Microscopes containing more than one magnifying lens.

Ocular Lens/Eyepiece

Lens at the top of the microscope, the viewer looks through to see the specimen.

Revolving Nosepiece

Part of the microscope located above the stage, holding the objective lenses.

Diopter Adjustment

Used to correct vision differences between eyes on a microscope.

Body Tube/Head

Connects the eyepiece to the objective lenses on a microscope.

Arm

Connects the body tube to the base of the microscope.

Coarse Adjustment

Microscope adjustment that brings the specimen into general focus.

Fine Adjustment

Microscope adjustment to fine-tune the focus and increase specimen details.

Objective Lenses

Lenses closest to the specimen, held by the nosepiece, ranging from 4X to 100X.

Stage

Flat platform beneath the revolving nosepiece where the specimen is placed.

Stage Clips

Metal clips above the stage that hold the slide in place.

Stage Control

Knobs beneath the stage to move it left/right or forward/backward.

Aperture

The hole in the middle of the stage that allows light to reach the specimen.

On/Off Switch

Switch at the base of the microscope to turn the illuminator on or off.

Illuminator

The light source of the microscope.

Iris Diaphragm

Adjusts the amount of light coming through the condenser.

Condenser

Lens system beneath the stage, focuses light onto the specimen.

Base

Supports the microscope and houses the illuminator.

Brightfield Microscope

Microscope using lenses and visible light to magnify objects.

Darkfield Microscope

Microscope that utilizes reflected light instead of transmitted light.

Electron Microscope

Microscopes using an electron beam as a source of illumination.

Staining

Used to give color to microorganisms, making them easier to see under the microscope.

Simple Staining

Use of a single dye to visualize cell shape, size, and arrangement.

Differential Staining

Staining used to differentiate one group of bacteria from another.

Gram Stain

Differential stain that distinguishes gram-positive from gram-negative bacteria.

Acid-Fast Stain

Stain used for bacteria with high lipid content in their cell wall.

Hot Method

Zeihl-Neelsen stain, requires steam-bathing after adding primary dye.

Cold Method

Kinyoun stain, does not utilize heat after addition of the primary stain.

Special Staining

Stains used to demonstrate specific structures in a bacterial cell.