Microscopy and Staining Techniques

Vocabulary flashcards covering concepts of microscopy types, light behaviors, specimen preparation methods, and staining classification from the lecture.

Refraction

The bending of light as it travels through different media or materials.

Resolution

The clarity of an image, specifically defined as the ability to distinguish two separate objects as distinct and separate.

Bacteriophages

Viruses that infect and kill bacteria.

Field of View

The circular area visible when looking into the eyepieces of a microscope.

Condenser

The component of a microscope that condenses a wide beam of light from the light source into a narrower beam focused onto the sample.

Bright Field Microscopy

A form of light microscopy where the field of view background is bright, often utilizing stained samples to enhance visibility.

Neisseria gonorrhoeae

The bacterium that causes gonorrhea, known for reproducing inside human white blood cells instead of being destroyed by them.

Dark Field Microscopy

A form of light microscopy that uses a condenser stop to block direct light, causing light to reflect off the sample so the background appears dark while the specimen is illuminated.

Spirochete

A corkscrew-shaped bacterium that is delicate and easily damaged by staining procedures.

Borrelia burgdorferi

A corkscrew-shaped spirochete bacterium that causes Lyme disease.

Treponema pallidum

A spirochete bacterium that causes syphilis.

Phase Contrast Microscopy

A light microscopy technique that separates and recombines two beams of light, using refractive differences in cell structures to produce a shaded, three-dimensional-looking image.

Differential Interference Contrast (DIC) Microscopy

A light microscopy technique similar to phase contrast that uses prisms to split light beams, creating colorful three-dimensional-appearing images.

Fluorochrome

A fluorescent dye or stain used to label samples for fluorescent or confocal microscopy.

Fluorescent Microscopy

A light microscopy technique where ultraviolet light excites electrons in fluorochrome-stained samples, causing them to emit visible light.

Confocal Microscopy

Microscopy that uses lasers, pinhole apertures, fluorochromes, and computer software to stack multiple optical planes into a three-dimensional image.

Transmission Electron Microscopy (TEM)

An electron microscopy technique where electron beams pass through a sample inside a vacuum to create detailed two-dimensional views of internal ultrastructures at high magnification.

Scanning Electron Microscopy (SEM)

An electron microscopy technique that scans electron beams over the surface of a specimen inside a vacuum to generate three-dimensional images of external structures.

Scanning Tunneling Microscopy (STM)

A probe microscopy method where a metal tip moves above a sample without touching it, measuring electrical current flow between tip and sample to map atomic features.

Atomic Force Microscopy (AFM)

An advanced probe microscopy method where a tip attached to a cantilevered arm touches the sample surface, using changes in a reflected laser angle to produce detailed images.

Wet Mount

A microscope slide preparation made by placing a liquid sample under a coverslip without heat fixing, preserving sample moisture to observe live cell movement.

Smear

A microscope slide preparation made by spreading a liquid sample on a slide, drying it, and heat fixing it prior to staining.

Heat Fixing

The process of heating a dried sample slide (e.g., on a slide warmer) to adhere specimen cells to the glass surface so they do not wash off during staining.

Positive Stain

A dye carrying a positive charge that binds to negatively charged organisms, directly staining the bacterial cells.

Negative Stain

A dye carrying a negative charge that is repelled by negatively charged cells, staining the background space around the unstained cells.

Simple Stain

A staining procedure that utilizes a single dye to enhance the overall visibility of cells.

Differential Stain

A staining procedure using two or more dyes (such as the Gram stain) to distinguish different types of cells or structures based on physical or chemical traits.