Histology - Intro to Histology Flashcards
, focused with optincal lens (max resoving poswr ~0.2 microns).
Light microscopy (LM)
Electrons interact with tissue components (B&W images). Focused with electromagnetic lens (resolution 1000x LM)
Electron microscopy (EM)
Shows internal structure
Transmission (TEM)
Shows external (surface) structure
Scanning (SEM)
splits cell membranes (p-face, e-face)
TEM freeze fracture technique
Interact with acids (basophilic structures). Stain acidic components blue or purple. E.g. nucleic acids (RNA< DNA, RER), glycosaminoclycans (GAGs)
Base-like stains
Interact with bases (acidophilic structures). Stain basic components pink, red, or orange. E.g. mitochondria, collagen
Acid-like stains
acid-like stain (reddish)
eosin
base-like stain (blue)
hematoxylin
Stains carbohydrates magenta. E.g., glycoproteins in mucin
Periodic-Acid Schiff (PAS)
coffee bean staining pattern of nucleus
Brenner tumor
Stains collagen fibers blue or green
Trichrome
Stains reticular fibers black
Silver
Stains elastic fibers reddish-brown or black
Orcein
stains lipids red
Sudan Red
stains lipids black
Osmic acid
Look at nuclei (tend to be similar in size among cells)
How to see scale
biological yardstick (~8 microns)
Red blood cell (RBS)
tissue shrinkage & lost molecules, “cracks” & “spaces”
Artifacts