Microbiology Study Guide: Bacterial Morphology and Staining

Vocabulary flashcards covering bacterial cell shapes, cell arrangement prefixes, differential staining components, and Gram staining basics from the Microbiology Study Guide.

Coccus (cocci)

A bacterial cell shape described as round or spherical.

Spirillum / spiral

A bacterial cell shape described as spiral-shaped.

Vibrio

A bacterial cell shape described as curved or comma-shaped.

Strepto-

A cell arrangement prefix meaning chains (e.g., Streptococcus = cocci in chains).

Staphylo-

A cell arrangement prefix meaning clusters (e.g., Staphylococcus = cocci in clusters).

Diplo-

A cell arrangement prefix meaning pairs (e.g., Diplococcus = cocci in pairs).

Differential Staining

A staining procedure that uses two or more dyes/reagents to distinguish microorganisms based on differences in their structures or staining properties.

Primary stain

The first dye applied in differential staining; initially colors the cells or target structure.

Mordant

A reagent that helps the primary stain bind more strongly or form a larger stain complex.

Decolorizer

A reagent that removes the primary stain from cells that do not retain it.

Counterstain

A second dye that makes decolorized cells easier to see.

Gram Staining

A differential-staining method that separates bacteria based on differences in their cell envelopes.