Natural dyes Flashcards
natural dye derived by extraction from the core or the
heartwood of a Mexican tree known as “Hematoxylin Campechianum”.
Hematoxylin
T/F.
Hematoxylin itself is not a true basic dye
True
active coloring agent of Hematoxylin
Hematin
formed by the oxidation of hematoxylin, a process known as “ripening.”
Hematin
Ripening takes as long as
3-4 months
Ripening can be accelerated by adding strong oxidizing agents such as
- hydrogen peroxide
- mercuric oxide
- potassium permanganate
- sodium perborate
- sodium iodate
excessive oxidation (over-ripening) leads to production of other
useless substances
T/F.
Using the least amount of oxidant will result in satisfactory staining and longer life of the stain.
True
seldom used alone due to its inherent low affinity for the tissue itself
Ripened Hematoxylin
Ripened Hematoxylin is most frequently used in combination with
- alum
- iron
- chromium
- copper salts
alum, iron, chromium and copper salts acts as
Mordant
substances that combine with the tissue and the staining solution, forming a “bridge” that allows staining reaction to take place.
Mordant
recommended for progressive staining of
tissues, and are usually counterstained with Eosin, Congo Red and Safranin.
Alum hematoxylin stains
Stains that contains Alum hematoxylin
- Ehrlich’s solution
- Harris’solution
Rapid ripening of Ehrlich’s reagent is brought about by the addition of
Sodium Iodate
Rapid ripening of Harris solution is brought about by the addition of
Mercuric Chloride
used only for differential or regressive staining
Iron hematoxylin compounds
differentiating agent used in Iron hematoxylin compounds
Acid-Alcohol
example of an IRON HEMATOXYLIN COMPOUND is
Weigert’s Stain
Weigert’s Stain uses
Iron (Ferric) Chloride
utilized for the study of spermatogenesis
Copper hematoxylin solutions
used frequently in histology to examine thin sections of tissue
Hematoxylin and eosin (H&E)
stains cell nuclei blue
Hematoxylin
stains cytoplasm, connective tissue and other extracellular substances pink or red
eosin
T/F.
H & E preparation the red blood cells are almost
orange
True
T/F.
collagen and cytoplasm (especially muscle) acquire different shades of pink
True
old histologic dye extracted from the female cochineal
bug (Coccus Cacti)
Cochineal dye
Cochineal dye treated with alum to produce the dye
carmine
T/F.
Cochineal dye is widely used as a powerful chromatin and nuclear stain for fresh material and smear preparations
True
Cochineal dye combined with picric acid
(picrocarmine)
(picrocarmine) is for
neuropathological studies
Cochineal dye combined with aluminum chloride
(Best’s carmine stain)
(Best’s carmine stain) is for
glycogen
vegetable dye extracted from certain lichens
Orcein
Orcein is normaly appears
colorless
Orcein treated with ammonia and exposed to air,
produces
blue or violet colors
T/F.
Orcein is a weak acid, is soluble in alkali, and is
mainly used for staining ELASTIC FIBERS.
True
also obtained from lichens, treated with lime and soda, and exposed to ammonia and air
Litmus
T/F.
Litmus is not used as a cytological stain because of its poor staining property. used mainly as an indicator.
True
