Staining

30問 • 2年前

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It gives histological sections color and make them visible

Staining

What is the result of staining?

1) morphologic changes are more easily identified 2) physical characteristics and structural relationships of tissues and their cells can be evaluated (by the pathologist) 3) the presence or absence of disease can be established

True/False: The components of cells that are acidic in character (e.g. nucleus) have greater affinity for basic dyes while basic constituents (e.g. cytoplasm) take more of acid stains. (basic cells attract acidic stains, acidic cells attract basic stains)

True

What are the different type of staining methods?

Counter staining Metachromatic staining Regressive staining Progressive staining Decolorization Direct staining Indirect staining Vital staining Intravital staining Supravital staining

The application of a different color or stain to provide contrast and background to the staining of the structural components to be demonstrated

Counter staining

Entails the used of specific dyes which differentiate particular substances by staining them with a color that is different from that of the stain itself

Metachromatic staining

Dyes which gives color blue

Toluone blue

-With this technique 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 color is obtained -With washing and decolorization

Regressive staining

-Is the 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 -No washing and decolorization

Progressive staining

It is the 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

Decolorization

The process of giving color to the sections by using aqueous or alcoholic dye solutions

Direct staining

The process where the action of dye is intensified by adding another agent or mordant which serve as a link or bridge between the tissue and the dye, to make staining reaction possible Ex. Gram’s iodine

Indirect staining

Selective staining of living cell constituents, demonstrating cytoplasmic structures by phagocytosis of the dye particle (cytoplasmic phagocytosis), or by staining of pre-existing cellular components (true vital staining). Ex. staining of mitochondria by Janus green

Vital Staining

Intravital staining of living cells is done by injecting the dye into any part of the animal body, producing specific coloration of certain cells, particularly those of the reticuloendothelial system Ex. lithium, carmine, India ink

Intravital staining

It is used to stain living cells immediately after removal from the living body Ex. methylene blue to stain nRBCs.

Supravital staining

What is the best vital dye?

Neutral red

Two types of dyes

Natural dyes Synthetic dyes

• are those obtained from plants and animals, previously utilized for dyeing of wool and cotton • Examples: Hematoxylin, Cochineal dyes and its derivatives, Orcein, Saffron

Natural dyes

-Known as "Coal Tar Dyes"

Synthetic dyes

Sythetic Dyes are derived from the hydrocarbon benzene and are collectively known as ______________.

Aniline dyes

What is the most common staining solutions?

Hematoxylin and Eosin

What are considered as Natural dyes?

Hematoxylin Cochineal Dyes Orcein

Derived by extraction from the core of the heartwood of a Mexican tree known Hematoxylin Campechianum

Hematoxylin

Extracted from the female cochineal bug Coccus Cacti, which is treated with alum to produce the dye carmine

Cochineal Dyes

Vegetable dye extracted from certain lichens

Orcein

These are substances with definite atomic groupings and are capable of producing visible colors

Chromophores

Classification of Chromophore Dyes

Acid dyes Basic dyes Neutral dyes

Where the coloring substance is found in the acid component.

Acid dyes

Where the active coloring substance is found in a basic component that combines with the acid radical.

Basic dyes

Formed by combining aqueous solutions of acid and basic dyes, capable of staining cytoplasm and nucleus simultaneously and differentially

Neutral dyes

Translation(Pre-finals)

MAHATHIR ALPHA · 55問 · 2年前

Translation(Pre-finals)