principles of staining Flashcards
– is the process of applying dyes on the sections to see and study the architectural pattern of the tissue and physical characteristics of the cells.
Staining
3 Major Groups of Staining
- Histological Staining
- Histochemical Staining
- Immunohistochemical Staining
-Process whereby the tissue constituents are demonstrated in sections by direct interaction with a dye or staining solution, producing coloration of the active tissue component.
Histological Staining
Stains in histological staining
a. micro-anatomic stains
b. bacterial stains
c. specific tissue stains
-various constituents of tissues are studied thru chemical reactions that will permit microscopic localization of a specific tissue substance
Histochemical Staining (Histochemistry)
Stains in Histochemical Staining (Histochemistry)
a. Perl’s Prussian Blue –>Hemoglobin
b. Periodic Acid Schiff –> CHO
-combination of immunologic and histochemical techniques that allow phenotypic markers to be detected and demonstrated under the microscope, using a wide range of polyclonal or monoclonal, fluorescent labeled or enzymelabeled antibodies
Immunohistochemical Staining
Methods of Staining
- Direct Staining
- Indirect Staining
Progressive Staining
Regressive Staining
Differentiation (Decolorization)
process of giving color to the sections by using aqueous or alcoholic dye solutions
e.g. methylene blue & eosin
Direct Staining
the action of the dye is intensified by adding another agent or MORDANT
Indirect Staining
serves as a link between the tissue and the dye
MORDANT
Examples of Mordant
Potassium alum w/ hematoxylin in Ehrlich’s hematoxylin
Iron in Weigert’s hematoxylin
accelerates or hastens the speed of the staining reaction by increasing the staining power and selectivity of the dye.
Accentuator
Examples of accentuator
Potassium hydroxide in Loeffler’s methylene blue
Phenol in Carbol thionine in carbol fuchsin
- Process whereby tissue elements are stained in a definite sequence and applied for a specific period of time
- it is not washed or decolorized
Progressive Staining
- The tissue is first overstained to obliterate the cellular details and the excess stain is removed or decolorized from
unwanted parts of the tissue, until the desired intensity of color is obtained
Regressive Staining
-selective removal of excess stain from the tissue during regressive staining
Differentiation (Decolorization)
acts differentiator for both Basic and Acid Dye
Alcohol
-use of specific dyes w/c differentiate particular substances w/ a color that is different from that of the stain itself
Metachromatic Staining
- tissue components combine w/ these dyes form a different color
- belongs to the thizine and triphenylmethane group
Metachromatic Staining
Metachromatic Staining
ex. 1. Methyl violet 6. Methylene blue
2. Cresyl blue 7. Thionine
3. Safranin 8. Toluidine blue
4. Bismark brown 9. Azure A and B
5. Basic fuchsin
True or False: All metachromatic dyes are cations or basic
true
-application of a different color or stain to provide contrast and background to the staining of the structural components to be demonstrated
Counterstaining
-specific tissue elements are demonstrated not by stains, but by colorless solutions of metallic salts
Metallic Impregnation
