Lecture 1 Background and history Flashcards
Prepare for staining
Paraffin removed from section using xylene
xylene removed using graded series alcohol down to water
Stains applied, section dehydrated through graded series of alcohols
Fixing
Prevents further deterioration, destorts specimen
Formalin
Hooke
Introduced the term cell
Basic dyes
Basophilic stains-Can stain RNA Methyl green Methylene blue Pyronene G Toluidine blue
Discovery that all living organisms are cells
Schwann and schleiden
Hematoxylin
Stains nuclear features, some cytoplasmic components
Orcein/resorcin fuchsin
Reveal elastic material
Bichat
Father of histology
Discovered 21 membranes w/o microscope
Saw life as divided into two parts- organic/animal
Leeuwenhoek
Made over 247 simple microscopes 100x magnification
Dehydrating
Remove water so sample can be embedded with hydrophobic paraffin
-uses ethanol
Confocal microscope
3d images, laser beam, monitor
Very thin images
Bouins fluid
Good cytological detail
Sudans
Stains lipids, can’t utilize alcohol for dehydration
Phase contrast
Examines living cells
Must be unstained
Schleiden
Botonist, recognized cell is essential unit of living organism
Pros/cons of compound
Ability to magnify, resolve structural detail
Specimen must be thin
Little contrast in unstained specimen
Embedding
Tissue is moved sequentially through 3 melted paraffin baths
Acid dyes
Aniline blue
Eosine
Orange G
Clearing
Replace alcohol with xylene or cedar oil
Zenkers fluid
Sharp histological detail, black crystals
Steps for staining
Fixing, dehydration, removal of alcohol, embedding
Carnoys fluid
Preserve glycogen
Best carmine
Demonstrates glycogen depists
Perls reaction
Demonstrate presence of iron
Silver impregnation
shows reticular fibers/basement membrane
Virchow
Pioneered concept of pathological processes through application of cell theory
Realized that all cells coming from existing cells could give insight into pathological processes
TEM staining
Uses ions of heavy metals
Eosin
Stains most cytoplasmic components and extracellular material
Metachromasia
Phenomenon whereby a dye changes colors after reacting with tissue component
-i.e. Toluidine blue when staining cartilage or mast cell granules
Fluorescence microscope
Detects fluorescence
Schwann
Zoologist, compared animal to plant cells
Jannsens
Produced first compound microscope
Kolliker
Embryology, wrote first textbook on it
Schiff reagent reactions
PAS- stains glucose/carbs
Fuelgen-stains deoxyribose
H&E
Most common stain, display structural features