Cytology and Histology Staining Vocabulary

Vocabulary flashcards covering key histology and cytology concepts, cell organelles, staining characteristics, sectioning planes, and histology artifacts.

Histology Staining

The process of coloring tissue to help identify structures and patterns by providing contrast in color, shape, texture, and organization.

Hematoxylin (H)

A positively charged (cationic), blue stain in H&E that binds well to acidic or negatively charged structures like DNA.

Eosin (E)

A negatively charged (anionic), red stain in H&E that binds well with basic or positively charged structures like proteins.

Basophilic Tissues

Tissues that stain blue in H&E, including nuclei, nucleoli, ribosome-rich cytoplasm, rough ER, and hyaline cartilage matrix.

Eosinophilic Tissues

Tissues that stain red in H&E, including protein-rich cytoplasm, muscle fibers, collagen fibers, and red blood cells.

Tissue Section

A slice of tissue that converts a three-dimensional structure into a two-dimensional structure for microscopic observation.

Plane of Section

The orientation of the cut through a three-dimensional tissue structure.

Level of Section

The specific location along a structure where the cut is made.

Longitudinal Section

A tissue cut made parallel to the long axis of a structure.

Transverse Section

A tissue cut made perpendicular to the long axis of a structure.

Oblique Section

A tissue cut made at an angle between the longitudinal and transverse axes.

Tangential Section

A tissue cut that barely passes through the edge of a structure.

Nucleus

An organelle that stores DNA and regulates gene function.

Nucleolus

A structure inside the nucleus that produces rRNA and assembles ribosomes.

Ribosomes

Cellular structures that synthesize proteins from mRNA.

Rough Endoplasmic Reticulum (RER)

An organelle that synthesizes secreted and membrane proteins.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins; it appears clear in standard staining because it is mostly membrane and hydrophobic.

Secretory Granules

Structures that store and release secreted products.

Plasma Membrane

A structure that controls cellular transport and signaling; it appears clear on slides because it is too thin to resolve directly.

Smooth Endoplasmic Reticulum (SER)

An organelle that synthesizes lipids, detoxifies, and stores calcium.

Mitochondria

Organelles that generate ATP through oxidative phosphorylation.

Cytoskeleton

A cellular framework that maintains cell shape and enables cellular movement.

Lysosomes

Organelles that digest and recycle cellular materials.

Lipid Droplet

A cellular structure that stores lipids for energy; it fails to stain and appears clear because lipids are extracted during tissue processing.

Euchromatin

Active, dispersed, 'easy to access' chromatin that displays lighter or paler staining.

Heterochromatin

Inactive, condensed chromatin that displays darker staining.

Glycogen

A cellular component that appears clear or fails to stain because it is extracted and poorly visualized during slide preparation.

Mucus

A cellular product that appears pale or clear on slides because it is poorly preserved.

Staining Artifacts

Unintended slide features resulting from tissue preparation, including tears, folds, chatter/knife marks, shrinkage, precipitates, and dissolution/extraction.

Chatter (Knife Marks)

An artifact characterized by parallel bands on tissue caused by microtome blade vibration.

Precipitates / Debris Artifacts

Brown or deep purple debris formed by unfiltered stain or acid-formalin reacting with blood.

Distinction of Artifacts vs. Real Tissue

Real tissue structures follow predictable patterns, whereas artifacts appear irregular or out of place.