HISTOPATHOLOGY Flashcards
(112 cards)
The process of applying dyes on the sections to see and study the architectural pattern of the tissue and the physical characteristics of the cells.
STAINING
acidic in character
* have greater affinity for basic dyes
Nucleus
basic constituent of the cell
CYTOPLASM
Tissues constituents are demonstrated in sections by direct interaction with a dye or staining solution, producing coloration of the active tissue component.
HISTOLOGICAL STAINING
Various constituents of tissues are studied through chemical reactions that will permit microscopic localization of specific tissue substances.
HISTOCHEMICAL STAINING (HISTOCHEMISTRY)
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 enzyme-labeled antibodies to detect and demonstrate tissue antigents.
IMMUNOHISTOCHEMICAL STAINING
process of giving color to the sections by using aqueous or alcoholic dye solutions.
direct staining
action of the dye is intensified by adding another agent or mordant.
indirect staining
It combines with a dye to form a colored “lake”, which in turn combines with the tissue to form a “tissue-mordant-dye-complex” that is rendered insoluble in ordinary aqueous and alcoholic solvents.
It is an integral part of the staining reaction itself, without which no staining could possibly occur.
mordant
Three ways to use mordant:
applied to the tissue before the stain
may be included as part of the staining technique
may be added to the dye solution itself.
Accelerates or hastens the speed of the staining reaction by increasing the staining power and selectivity of the dye.
ACCENTUATOR
A process whereby tissue elements are stained in a definite sequence and the staining solution is applied for specific periods of time or until the desired intensity of coloring of the different tissue elements is attained.
progressive staining
method of staining where the dye is not washed or decolorized
progressive
the tissue is first overstained to obliterate the cellular details, and the excess stain is removed or decolorized
regressive
Selective removal of excess stain from the tissue during regressive staining in order that a specific substance may be stained distinctly from the surrounding tissues.
DIFFERENTIATION (DECOLORIZATION)
This is usually done by washing the section in a simple solution (e.g.
water or alcohol), or by the use of acids and oxidizing agents.
DIFFERENTIAL STAINING
entails the use of specific dyes which differentiate particular substances.
Metachromatic staining technique
Uses more than one chemical stain to better differentiate between various microorganisms or structures/cellular components of a single organism.
Differential Staining
_____ is necessary for most metachromatic staining techniques, and metachromasia is usually lost if the section is dehydrated in alcohol after staining.
water
The property to stain biological materials with a color that is different from that of the stain itself.
METACHROMASIA
application of a different color or stain to provide contrast and background to the staining of the structural components to be demonstrated.
COUNTERSTAINING
process where specific tissue elements are demonstrated, not by stains, but by colorless solution of metallic salts
metallic impregnation
metallic impregnation produces ______ on surface of tissue or bacteria.
opaque, usually black deposit
the selective staining of living cell constituents, demonstrating cytoplasmic structures by phagocytosis of the dye particle (cytoplasmic phagocytosis).
vital staining