Connective Tissue Staning Flashcards
Role of Fibroblasts
Produce collagenic fibres and extracelluar matrix which consists of proteins.
Spindle morphology under microscope
3 components making up connective tissue
Cells:
Fat cells - store lipids
Fibroblasts - make collagen fibre and ex cell matrix
Fibres
Extra cellular matrix
4 types of connective tissue and their purpose
Dense - capsule around organs
Bone - cartilage rigid and support body weight
Muscular - power for contraction
Fibrin and fibrinoid - insoluble fibrillation protein (fibrinogen polymerisation)
Type 1 collagen staining
Collagen = anionic (-ve) so has affinity for acidic (+ve) dye
Stained selectively with weigarts heamatoxylin and Van Gieson counter stain
Or
Stained using sequential combo of dyes (trichrome - MSB)
Colours seen in Weigarts Haematoxylin and Van Gieson staining for reticular fibre staining
Nuclei - Black
Collagen, rbc, muscle - red
Cytoplasm - yellow
Reticular fibres
Fibres connecting to stronger collagenous fibres
Support cellular organs (spleen, liver, lymph nodes)
Where are Elastic fibres mainly found?
Heart, lung, skin
What are elastic fibres
Yellow fibres = Bundle of protein (elastin) found in ECM produced by fibroblasts
They stretch and snap back to original shape
How is Elastin stained?
Verhoeff (iron haematoxylin) - elastin has strong affinity for it
Van Gieson counterstain for collagen
Colours seen in elastin stain?
Verhoeff:
Elastic fibres & Nuclei - Black
Van Gieson:
Collagen, muscle, rbc - Red
Cytoplasm - yellow
What is a trichrome stain
Contain 3 different dyes
1 rep nuclei
1 rep collagen
1 rep cytoplasm, rbc, fibres
Trichrome mechanism
Small dye penetrates all 3 - stain rbc
Med penetrates muscle & collagen (not rbc bc already saturated)
Large penetrates muscle
Martius Scarlet Blue mechanism (trichrome)
Orange - rbc, cytoplasm/muscle, collagen - rbc = orange, wash out rest
Yellow - cytoplasm/muscle, collagen. Phosphotungstic acid removes yellow from collagen. Cytoplasm/muscle = yellow
Blue - collagen, rinse, dehyd & mount
Identify good MSB stain
Red/orange, yellow, blue
Distinguish dermal thickening (scleroderma) and fibrosis with MSB
Dermal thickening - different shades of pink, white centre
Fibrosis - dark blue, wine red and white centre
