Histology Stains Quiz: Principles of Histological Staining Lecture 4

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Questions and Answers

Why do we need to stain tissue sections?

To obtain useful clinical information (correct)

To prevent tissue sections from being transparent

To make tissue sections transparent

To demonstrate tissue elements only for research purposes

Which type of staining is used to selectively demonstrate tissue elements within tissue sections for research purposes?

Special Stains (correct)

Routine morphological staining

Immunohistochemistry

Vital stains

What happens to tissue sections when they are prepared without staining?

They become discolored

They remain transparent (correct)

They become rigid

They become too dark to analyze

What is the main purpose of immunohistochemistry?

To demonstrate tissue elements selectively Signup and view all the answers

Which method of staining is used to visualize specific proteins or antigens in tissue sections?

Immunohistochemistry Signup and view all the answers

What is the purpose of vital stains in histology?

To examine living cells or tissues Signup and view all the answers

What is the main component of cells, making up 80% of their composition?

Water Signup and view all the answers

What type of epithelium is characterized by a single layer of tall, narrow cells with their nuclei located near the base of the cells?

Simple columnar epithelium Signup and view all the answers

What is the function of goblet cells in the intestinal epithelium?

Secretion of mucus Signup and view all the answers

Which component of the small intestine is most affected by gluten sensitivity (coeliac disease), resulting in flattened mucosal surface?

Villi Signup and view all the answers

What is the main purpose of histological staining?

To deposit markers or characteristic colors on biological entities Signup and view all the answers

What is the initial step required to prepare formalin-fixed paraffin-embedded (FFPE) sections for staining?

Removal of wax Signup and view all the answers

What happens during the process of staining tissue sections with an aqueous staining solution?

Dyes and reagents enter tissues due to coulombic attractions Signup and view all the answers

What is the final step in preparing stained tissue sections to be permanent?

Mounting with coverslip using media Signup and view all the answers

What is the purpose of rehydrating formalin-fixed paraffin-embedded (FFPE) sections before staining?

To facilitate penetration of staining solutions into tissues Signup and view all the answers

What is the main purpose of acidic stains in histology?

To owe their colour to the anion, with sodium usually being the cation Signup and view all the answers

What is the main characteristic of basic stains in histology?

They owe their colour to the cation, with the anion commonly being a chloride Signup and view all the answers

What distinguishes neutral stains from acidic and basic stains in histology?

They owe their colour to both acid and basic elements, staining 'neutral' elements Signup and view all the answers

What is the main purpose of enzyme histochemical staining in histology?

To react with added substrate and a chromogen to produce a coloured insoluble end product Signup and view all the answers

What is the main purpose of immunohistochemical staining in histology?

To bind selectively to antigens in cells and/or tissues Signup and view all the answers

What is the main effect of neutral stains on tissue sections in histology?

To owe their colour to both acid and basic elements, staining 'neutral' elements Signup and view all the answers

What is the purpose of using a mordant in conjunction with haematoxylin?

To create a 'dye lake' with a positive charge Signup and view all the answers

Why are sections stained with routine basic dyes usually mounted in non-aqueous media?

To prevent dye extraction Signup and view all the answers

What is the reason for stains not being taken up into every part of the tissue?

Rate of reagent uptake Signup and view all the answers

How does fixation affect staining?

Different fixatives retain substances to different extents Signup and view all the answers

What influences staining in specimen geometry?

All of the above Signup and view all the answers

What is the primary factor affecting sensitivity in demonstration methods?

Retention of target in tissues Signup and view all the answers

What are the main aims of the Haematoxylin & Eosin (H&E) stain?

Add contrast to sections and react with specific targets Signup and view all the answers

Why do staining protocols vary between laboratories?

To account for differences in laboratory conditions and preferences Signup and view all the answers

What does the acronym 'SOP' stand for in the context of staining protocols?

Standard Operational Procedure Signup and view all the answers

How does specimen geometry influence staining equilibrium?

Complex geometries can arise when preparing smears from epithelia Signup and view all the answers

What is an artifact related to poor section cutting that produces sections comprised of alternating thick and thin strips?

Chatter Signup and view all the answers

What is the primary purpose of demonstration methods in histological staining?

To add contrast to sections Signup and view all the answers

Study Notes

Histological Staining

Tissue sections need to be stained to visualize tissue elements and structures.
Special stains are used to selectively demonstrate specific tissue elements for research purposes.

Preparation of Tissue Sections

Without staining, tissue sections are difficult to interpret and may appear transparent.
Immunohistochemistry is used to visualize specific proteins or antigens in tissue sections.
The main component of cells is water, making up 80% of their composition.

Types of Epithelium

Simple columnar epithelium is characterized by a single layer of tall, narrow cells with their nuclei located near the base of the cells.
Goblet cells in the intestinal epithelium produce mucin, which helps to lubricate and protect the intestine.

Gluten Sensitivity

The component of the small intestine most affected by gluten sensitivity (coeliac disease) is the mucosal surface, resulting in a flattened appearance.

Histological Staining Purpose

The main purpose of histological staining is to enhance the visibility of tissue structures and components.

Preparing FFPE Sections

The initial step in preparing formalin-fixed paraffin-embedded (FFPE) sections for staining is to rehydrate them.
Rehydrating FFPE sections allows for the removal of paraffin and the restoration of the tissue's natural structure.

Staining Process

During staining, an aqueous staining solution penetrates the tissue section, and the dye binds to specific tissue components.
The final step in preparing stained tissue sections is to mount them in a medium, such as a solvent, to make them permanent.

Stain Characteristics

Acidic stains are used to stain basophilic structures, such as nuclei and cytoplasm.
Basic stains are used to stain acidophilic structures, such as collagen and cytoplasmic inclusions.
Neutral stains do not have a specific affinity for acidic or basic structures and are used to stain general tissue structures.

Enzyme and Immunohistochemical Staining

Enzyme histochemical staining is used to demonstrate the activity of enzymes in tissue sections.
Immunohistochemical staining is used to detect specific proteins or antigens in tissue sections.

Stain Effects

Neutral stains have a general staining effect on tissue sections.
Acidic stains are negatively charged and bind to positively charged tissue components.
Basic stains are positively charged and bind to negatively charged tissue components.

Mordant and Haematoxylin

A mordant is used in conjunction with haematoxylin to enhance the staining of basophilic structures.

Mounting Stained Sections

Sections stained with routine basic dyes are usually mounted in non-aqueous media to prevent the dye from being washed out.

Stain Uptake

Stains are not taken up into every part of the tissue due to variations in tissue structure and composition.

Fixation and Staining

Fixation affects staining by altering the tissue's structure and composition, which can affect the binding of dyes.

Specimen Geometry and Staining

Specimen geometry influences staining equilibrium, which can affect the uniformity of staining.

Sensitivity and Demonstration Methods

The primary factor affecting sensitivity in demonstration methods is the amount of antigen or protein present in the tissue section.
The primary purpose of demonstration methods is to visualize specific tissue components or structures.

Haematoxylin & Eosin (H&E) Stain

The main aims of the Haematoxylin & Eosin (H&E) stain are to provide a general overview of tissue structure and to identify specific tissue components.

Staining Protocols and SOP

Staining protocols vary between laboratories due to differences in equipment, reagents, and personnel.
SOP stands for Standard Operating Procedure, which outlines the step-by-step protocol for a specific staining technique.

Specimen Geometry and Staining Equilibrium

Specimen geometry influences staining equilibrium, which can affect the uniformity of staining.

Artifacts in Staining

A chunking artifact is related to poor section cutting and produces sections comprised of alternating thick and thin strips.

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Description

Test your knowledge on the principles and theory of histological staining with this quiz. Learn about the main types of staining actions and enhance your understanding of the techniques used in pathology.

Histological Staining Principles Lecture 4 Quiz

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