Microscopy, Staining, and Taxonomy Vocabulary

A set of vocabulary flashcards covering microscopy concepts, light and electron microscope types, staining methods, and taxonomic classification principles.

Wavelength

The distance between 2 points of a wave.

Magnification

The process or degree of making an object appear larger.

Resolution

The ability to distinguish two close objects as separate.

Contrast

The difference in intensity between an object and its background.

Simple microscope

A microscope containing 1 magnifying lens (similar to a magnifying glass), which Leeuwenhoek used to observe specimens.

Compound microscope

A microscope utilizing a series of lenses (1 or 2 ocular lenses) where light passes through the specimen to the objective lens, assisted by a condenser, with oil immersion used to increase resolution.

Dark-field microscopy

A light microscopy technique best for pale objects where only light scattered by the specimen enters the objective, making the specimen appear light against a dark background.

Phase microscopy

Microscopy useful for living organisms or specimens damaged by staining, which creates contrast using differences between in-phase light (brighter) and out-of-phase light (darker).

Fluorescent microscope

A microscope that uses UV light to excite a specimen, causing it to emit energy as a longer, visible wavelength, thereby increasing resolution and contrast.

Immunofluorescence

A technique using fluorescent dyes attached to antibodies that bind specific antigens, used to identify pathogens or make specific proteins visible.

Confocal microscopy

A technique using fluorescent dyes and UV lasers to illuminate fluorescence in a single plane, employing a pinhole aperture to improve resolution while a computer combines images into a 3-D image.

Transmission electron microscope (TEM)

An electron microscope in which electrons pass through a specimen to observe internal ultrastructure, generating highly magnified 2-D images.

Scanning electron microscope (SEM)

An electron microscope in which electrons scan the specimen surface to reveal surface details with a 3-D appearance.

Probe microscopy

Microscopy capable of magnifying $100,000,000+$ times, which includes scanning tunneling microscopes and atomic force microscopes.

Chromophore

The colored part of a dye molecule.

Acidic dyes

Dyes that carry a negative charge and stain alkaline structures.

Basic dyes

Dyes that stain acidic structures; they are more common in microbiology because most cell surfaces are negatively charged.

Simple stains

Stains that use a single dye to reveal general cell size, shape/morphology, and arrangement.

Differential stains

Staining techniques used to distinguish between different types of cells or cellular structures, including the Gram stain, acid-fast stain, and endospore stain.

Special stains

Stains used to reveal specific cellular structures, including negative/capsule stains and flagellar stains.

Gram staining procedure (CIDS)

A 4-step differential stain using Crystal violet (primary stain), Iodine (mordant), Alcohol/acetone (decolorizer), and Safranin (counterstain); results in Gram-positive cells appearing purple and Gram-negative cells appearing pink.

Ziehl-Neelsen acid-fast stain

A differential stain where acid-fast cells stain pink/red and non acid-fast cells stain blue.

Schaeffer-Fulton endospore stain

A differential stain that colors endospores green and vegetative cells pink/red.

Negative / Capsule stain

A special stain that colors the background while leaving cells unstained or stained differently, revealing the bacterial capsule.

Flagellar stain

A special stain that makes bacterial flagella visible, helping determine their number and location.

Taxonomy

The science of classification (organizing into groups), nomenclature (naming), and identification (determining identity).

Linnaeus

The scientist who classified organisms by shared characteristics, used the species category, and developed binomial nomenclature.

Carl Woese

The scientist who compared rRNA nucleotide sequences, leading to the development of the 3-domain system (Bacteria, Archaea, Eukarya).

Serological tests

Identification tests that rely on specific reactions between antibodies and antigens.

Phage typing

An identification method testing bacterial susceptibility to specific bacteriophages, identified by plaque formation.

Dichotomous keys

Tools that identify organisms through a step-by-step series of paired either/or choices.