Stains and Staining Solutions

A collection of flashcards covering key terms and definitions related to biological stains and staining solutions.

Natural Dyes

Dyes obtained from plants and animals, used for dyeing wool and cotton, e.g., hematoxylin, cochineal dyes.

Synthetic Dyes

Also known as 'coal tar dyes', these are manufactured from substances derived from coal tar, e.g., aniline dyes.

Hematoxylin

A natural dye derived from the heartwood of the tree 'hematoxylin campechianum', used as a powerful nuclear stain.

Cochineal Dyes

Dyes extracted from the female cochineal bug, used for staining chromatin and nuclei.

Orcein

A vegetable dye from lichens used for staining elastic fibers, typically not a cytological stain.

Acid Dyes

Dyes where the active coloring substance is in the acid component; used for staining tissues.

Basic Dyes

Dyes where the active coloring substance is in a basic component, used for staining acidic cell structures.

Neutral Dyes

Combinations of acid and basic dyes used to stain both the cytoplasm and nuclei simultaneously.

Mordants

Substances used to fix dyes onto tissues by forming links with the dye molecules.

Alum

A chemical compound commonly used as a mordant in hematoxylin staining.

Blueing

The process of converting reddish nuclear coloration of hematoxylin to a crisp blue/purple for enhanced contrast.

Chromogen

A molecule that contains chromophores but does not permanently stain tissues.

Auxochrome

An auxiliary group that allows coloring compounds to retain their color and form salts.

Picric Acid

An acid dye that can fix, differentiate, or stain tissues on its own.

Giemsa Stain

A stain used to differentiate leukocytes in blood smears and to highlight certain tissue structures.

Eosin

An acidic dye used primarily as a counterstain that provides a pink/red color to connective tissues.

Sudan Black

A lysochrome dye used to stain phospholipids and neutral fats black.

Periodic Acid Schiff

A staining method that detects glycogen and mucins through selective oxidation.

Alcian Blue

A water-soluble pthalocyanin dye that stains acidic mucins blue in tissue samples.

Aniline Dyes

Synthetic dyes derived from coal tar, which include chromogens that allow for visible color.

Carmine

A dye produced from cochineal bugs, often used for staining in histology.