Lecture 1 Systems: Introduction to cytology

Hematoxylin

Plant dye combined with metal ion to become a blue positively charged (cationic) dye. Binds to basophilic things.

Hematoxylin dye color

Dark blue/purple stain

Eosin

fluorescent red dye derived from fluorescin. Negatively charged (anionic) loves eosin.

What color does eosin stain?

pink/orange/red

What kinds of things does hematoxyalin dye?

nucleic acids, nueclus, ribosomes, rough ER, hyaline cartilage matrix, secretory granules

What kinds of things does eosin stain?

proteins, collagen, muscle fibers, etc (cytoplasm and matrix), red blood cells, mitochondria, cytoskeleton, secretory granules

What do tissue sections allow us to do?

study microanatomy by seeing 3D structures as 2D

What we see on a slide depends on what?

3D organization, stain used, plane of section, and level of section

Plane of section

Describes orientation of the cut. Types: longitudinal, transverse, oblique

Level of section

Describes where along the structure the cut is made so high or low

Longitudinal section

cut parallel to long axis

transverse section (cross section)

cut perpendicular to long axis

oblique section

cut at an angle between longitudinal and cross section (diagonal ish)ta

tangential section

cut barely passes through the edge of a structure

Euchromatin

dispirsed chromatin, lighter staining, transcriptionally active

Heterochromatin

condensed chromatin, darker staining, less transcriptionally active (inactive)

Poorly stained structures in H&E

lipid droplets, golgi, glycogen (sugar), mucus, plasma membrane

There are lot of steps in prepating H&E slides. What does that mean/why is this revelant?

A lot of changes can happen to orginal tissue/sample and artifacts can occur

Common artifacts

tears, folds, chatter/knife marks, shrinkage, precipitates, dissolution/extraction