Histology Tissue Preparation
45 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of a cytologist examining cells obtained from body tissue or fluid?

  • To study the function of cells in terms of chemistry
  • To identify the type of stain used in cytology
  • To look for cancerous changes to cells (correct)
  • To examine the structure of cells

    • What type of cytology specimen is obtained from the respiratory, urinary, or gastro-intestinal systems?

  • Non-gynaecological (correct)
  • Gynaecological
  • Fine needle aspirations
  • Cervical smears

    • What is the name of the staining technique that involves five dyes in three solutions?

  • Romanowsky-type stain
  • Giemsa stain
  • Papanicolaou stain (correct)
  • Hematoxylin and Eosin stain

    • What is the purpose of using Harris' hematoxylin in the Papanicolaou staining technique?

    <p>To stain cell nuclei blue</p> Signup and view all the answers

    What is the name of the type of cytology specimen that includes any site from which a clinician can obtain a specimen using a fine needle?

    <p>Fine needle aspirations</p> Signup and view all the answers

    What is the name of the stain used to differentiate cells for microscopic examination in pathological studies?

    <p>Romanowsky-type stain</p> Signup and view all the answers

    What is the name of the collection device used to collect cervical smears?

    <p>Rover Cervex Brush</p> Signup and view all the answers

    What is the minimum number of years that slides must be kept in cytology?

    <p>5 years</p> Signup and view all the answers

    What is the term for the study of cells in terms of structure, function, and chemistry?

    <p>Cytology</p> Signup and view all the answers

    What is the purpose of increasing the temperature of fixation?

    <p>To increase the rate of diffusion of the fixative into the tissue</p> Signup and view all the answers

    What is the recommended minimum time for fixation of a 4 mm piece of tissue?

    <p>8 hours</p> Signup and view all the answers

    Which of the following fixatives is commonly used for electron microscopy?

    <p>Glutaraldehyde</p> Signup and view all the answers

    What is the primary purpose of the gross description in histology?

    <p>To create a written record of the examiner's findings</p> Signup and view all the answers

    What is the purpose of the cassette labeler in histology?

    <p>To etch the numbers on the cassette</p> Signup and view all the answers

    What is the purpose of the dehydration step in tissue processing?

    <p>To remove water from the tissue and replace it with alcohol</p> Signup and view all the answers

    What is the purpose of the clearing step in tissue processing?

    <p>To remove ethanol from the tissue and replace it with xylene</p> Signup and view all the answers

    What is the typical temperature at which paraffin wax is infiltrated into tissue?

    <p>60°C</p> Signup and view all the answers

    What is the purpose of adding additives to paraffin wax?

    <p>To improve the consistency of paraffin wax</p> Signup and view all the answers

    What is the primary function of the histology department?

    <p>To prepare slides of tissue from various sources for pathologist examination</p> Signup and view all the answers

    What is the purpose of fixation in histology?

    <p>To preserve tissue and prevent structural change</p> Signup and view all the answers

    What is the common brand name of the paraffin wax used in the embedding process?

    <p>Paraplast</p> Signup and view all the answers

    What is the temperature of the embedding oven in the wax infiltration step?

    <p>60-degree C</p> Signup and view all the answers

    What is the most common fixative used in histology?

    <p>10% formalin</p> Signup and view all the answers

    What is the advantage of using 10% N.B. formalin as a fixative?

    <p>It penetrates tissue rapidly and preserves the natural state</p> Signup and view all the answers

    What is the purpose of adding an external base to the tissue during the embedding process?

    <p>To make the tissue more stable</p> Signup and view all the answers

    How is 10% formalin prepared?

    <p>By mixing 40% formaldehyde with 100ml of water</p> Signup and view all the answers

    What is the thickness of the sections cut on a microtome?

    <p>3-5 um</p> Signup and view all the answers

    What is the purpose of the hot water bath in the staining process?

    <p>To flatten and remove wrinkles from the sections</p> Signup and view all the answers

    What is the difference between formaldehyde and formalin?

    <p>Formaldehyde is a mixture of formaldehyde gas and water, while formalin is the addition of methyl alcohol to formaldehyde</p> Signup and view all the answers

    What is the solvent used to remove wax from the sections during the staining process?

    <p>Xylene</p> Signup and view all the answers

    Why is it necessary to add a buffer to formalin?

    <p>To neutralize the pH of the solution</p> Signup and view all the answers

    What is the purpose of the dehydration step in the permanent mounting process?

    <p>To prepare the sections for mounting</p> Signup and view all the answers

    What is the ideal ratio of fixative to specimen volume?

    <p>15-20:1</p> Signup and view all the answers

    What is the advantage of using frozen sections over paraffin wax embedding?

    <p>Faster processing time</p> Signup and view all the answers

    What is the order of steps in preparing histological sections?

    <p>Fixation, embedding, sectioning, staining</p> Signup and view all the answers

    What should you do with small amounts of ethyol alcohol?

    <p>Pour it down the drain</p> Signup and view all the answers

    What is the primary purpose of the cytocentrifuge?

    <p>To transfer biological cells from liquid suspension onto a microscope slide</p> Signup and view all the answers

    What is the purpose of the ThinPrep 2000 processor?

    <p>To prepare cervical smears for cytology</p> Signup and view all the answers

    What is the role of a Medical Laboratory Assistant (MLA) in histology?

    <p>To perform routine tissue processor maintenance and reagent changes</p> Signup and view all the answers

    What is the purpose of Histogel in cell block preparation?

    <p>To harden the specimen block in the centrifuge tube</p> Signup and view all the answers

    What is the purpose of the supernatant removal in cell block preparation?

    <p>To remove remaining specimen for cell block preparation</p> Signup and view all the answers

    What is the role of a Medical Laboratory Assistant (MLA) in cytology?

    <p>To prepare specimens for cytology</p> Signup and view all the answers

    What is the purpose of securely tightening the cap on the vial?

    <p>To ensure the specimen is safely transported to the lab</p> Signup and view all the answers

    What is the purpose of the Cytology fixed spray?

    <p>To fix the slide for cytology</p> Signup and view all the answers

    What is the purpose of placing the specimen block on tissue paper?

    <p>To wrap the specimen block for processing</p> Signup and view all the answers

    Study Notes

    Histology and Cytology

    Purpose of Histology Department

    • Prepare slides of tissue from various sources for pathologist examination

    Preparation of Histological Sections

    • Steps:
    • Preserve tissue (fixation)
    • Embed tissue in supporting medium
    • Sectioning
    • Staining

    Fixation

    • Purpose: preserve tissue, prevent structural change
    • Fixative: 10% Neutral Buffered (N.B.) Formalin
    • Characteristics of Formalin:
    • Cheap
    • Rapidly penetrates tissue
    • Preserves natural state
    • Made by mixing 40% Formaldehyde with 100ml water
    • To get 10% Formalin, mix 10ml of 100% Formalin with 90ml water

    Factors Affecting Fixation

    • Temperature: increases rate of fixation
    • Time: longer time generally better
    • Penetration rate: depends on fixative
    • Specimen dimensions: 1-4 mm thickness

    Other Fixatives

    • Bouin's solution: picric acid
    • Zenker's fixative: mercuric chloride
    • Glutaraldehyde: electron microscopy
    • Alcohols: good for cytology

    Tissue Processing

    • Steps:
    • Dehydration (removal of water using ascending series of alcohols)
    • Clearing (using xylene to displace ethanol)
    • Wax infiltration (paraffin wax)
    • Can be done manually or by machine (HistoCore PELORIS 3 Premium Tissue Processing System)

    Embedding

    • Purpose: stabilize tissue with external base
    • Process: place tissue in mold, add hot wax, and cool to form a wax block

    Microtomy

    • Process: cut sections of tissue embedded in wax block using a microtome
    • Thickness: 3-5 um

    Staining

    • Most common stain: Hematoxylin and Eosin (H&E)
    • Steps:
    • Remove wax using xylene
    • Hydrate sections using descending alcohols and water
    • Stain with Hematoxylin and Eosin

    Permanent Mounting

    • Steps:
    • Dehydrate sections using ascending alcohols
    • Clear using xylene
    • Mount with a mountant (e.g. Permount) and glass coverslip

    Cytology

    • Definition: study of cells in terms of structure, function, and chemistry
    • Objectives:
    • Different types of cytology specimens
    • Procedures used in cytology
    • Common stains used in cytology
    • Papanicolaou stain

    Types of Cytology Specimens

    • Gynaecological (cervical cancer)
    • Non-gynaecological (respiratory, urinary, gastro-intestinal systems)
    • Fine needle aspirations (breast, lung, salivary glands, etc.)

    Stains Used in Cytology

    • Papanicolaou stain (for nuclear details)
    • Romanowsky-type stain (for acid-fast bacteria)

    Papanicolaou Stain

    • Five dyes in three solutions:
    • Hematoxylin (nuclear stain)
    • Orange Green 6 (acidic counterstain)
    • Eosin Azure (counterstain)
    • Eosin Y (cytoplasmic stain)
    • Light green SF (cytoplasmic stain)

    Specimen Preparation

    • Various methods:
    • Cytocentrifugation preparation (Cytospin)
    • ThinPrep preparation (mainly for cervical smears)
    • Cell block preparation (captures remaining specimen in centrifuge tube)

    Role of a MLA in Histology/Cytology

    • Prepares specimens for histology
    • Labels tissue cassettes
    • Performs routine tissue processor maintenance and reagent changes
    • Files and retrieves stained slides and paraffin blocks
    • Performs routine staining procedures
    • Mounts slides
    • Assists in the cutting room
    • Prepares specimens for cytology
    • Stains and mounts pap slides

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Learn about the process of preparing histological sections, including fixation, embedding, sectioning, and staining, in a histology department.

    More Like This

    Histotechniques: Tissue Preparation for Microscopic Study
    5 questions

    Histotechniques: Tissue Preparation for Microscopic Study

    PoliteSerpent avatar
    PoliteSerpent
    Histology Tissue Preparation
    36 questions

    Histology Tissue Preparation

    WorthyChaparral avatar
    WorthyChaparral
    Histology Fundamentals
    46 questions

    Histology Fundamentals

    LikedTajMahal avatar
    LikedTajMahal
    Tissue Preparation and Histology Quiz
    12 questions

    Tissue Preparation and Histology Quiz

    TenaciousLogic7873 avatar
    TenaciousLogic7873
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser