Histopath Flashcards
(131 cards)
METHODS OF TISSUE EXAMINATION:
___
- Examined in its living state
- Allows examination of protoplasmic activities (mitosis, phagocytosis, pinocytosis, motility)
- Tissues are not permanent
Methods of FRESH TISSUE EXAMINATION:
○ Teasing or Dissociation
- Tissue is immersed in a watch glass with NSS
- Dissected or separated
- Examined under the microscope (phase contrast or bright field); Stained with methylene blue
○ ___ (Crushing): Small tissues (1mm or less) placed in a slide; Tissues are Compressed with another slide or coverslip. Supravital stains can be added
○ ___ = Cellular materials are spread lightly over a slide & useful for cytology
- ___: material is added using an applicator stick or loop in a direct or zigzag fashion
- ___: material is placed on a clean slide and spread into a moderately thick film by teasing with an applicator stick. Advantage: maintains intercellular relationships
- ___: use of 2 slides in preparing the smear; for thick secretions
- ___: (AKA: Impression smear) Freshly cut piece of tissue is brought into contact and pressed on to the surface of a clean slide; sllide is sterile & polished edges
- ___: Rapid Diagnosis
* Demonstration of lipids, nervous tissue elements, enzymes Apparatus: Cryostat, Cold microtome, Freezing microtome
FRESH TISSUES
Squash Preparation
Smear Preparation
Streaking
Spreading
Pull-Apart
Touch Preparation
Frozen Section
HISTOPATHOLOGY TECHNIQUES
1. ____: first and most important step in histopathology. Identify properly all the specimens received without the need of writing the patient’s name to the accompanying specimen tag. Entering the details of the specimen in a log book. In numbering, the specimen number is preceded by either S(__), A(__) or C(__). The year is also indicated. After numbering, the pathologist will describe the gross description of the specimen. The MT w down the description at the back of the request. Use __ in writing the description of the tissue specimen. Specimen size for Processing: ____ and ___ thick; for EM size is ___
NUMBERING (Accessioning)
surgical, autopsy, cytology
pencil
2x3cm; 3-5mm
1mm³
- ___: process of preserving cells adn tissue constituents in a condition identical to that existing during life. Prevents ___.
2 Important Goals of Fixation:
i. Preserve the morphological and chemical integrity of the cell
ii. Harden and preserve tissue for further handling
Methods of Fixation:
1. Heat Fixation
2. Perfusion - fixation via blood flow (embalming)
3. Immersion
Two Mechanisms of Action:
___: the fixative becomes part of the tissue by formation of crosslinks/complexes; stabilizes the tissue proteins; Examples: formalin, mercury, osmium tetroxide
___: fixative NOT incorporated into the tissue; alteration of the tissue composition; stabilizes the tissue by removing water. Examples: alcoholic fixatives
GENERAL EFFECTS OF FIXATIVES
Harden Soft and Friable Tissues for easy handling
Make cells resistant to damage and distortion Inhibits bacterial decomposition
Increase optical differentiation of cells
Act as mordants or accentuators
Reduce risk of infections
FIXATION
autolysis
additive
non-additive
FACTORS INVOLVED IN FIXATION
1. pH: ____
2. Temperature:
Traditionally at: ___
Autotech: ___
EM and Histochem at: ___
Rapid Fixation: __
For tissues w/ TB: __
- Thickness (Dimension of tissue):
EM: __
LM: __
*Tissues should not be more than 4 or 5 mm thick except in ___
Brain Tissue: suspended in __ for 2-3 weeks
Large Solid Tissues: uterus (open or sliced thinly)
6-8
room temp
40°C
0-4°C
60°C
100°C
1mm³/1-2mm²
2x3cm/2cm²
edematous lung tissue (10-20mm/1-2cm)
10% whole buffered formalin
- Osmolality: Slightly Hypertonic Solution around ___
- Concentration:
○ 10% Formalin
○ 3% Glutaraldehyde
○ ___: ideal for immunoelectron microscopy - Time Duration: Primary Fixation (__) in buffered formalin EM: fixation of ___ then placed in a holding buffer
PRACTICAL CONSIDERATIONS:
1. Speed: (<1hr): prevents autolysis & putrefaction
2. Rate of Penetration: Formalin __
3. Volume:___ times that of the tissue: (ideal ratio) ___
○ For expensive fixatives: ___
○ Museum Preparations: ___
4. Duration: depends on the tissue structure
○ Fibrous tissues: longer fixation time
○ Small or Loosely Textured Tissues: shorter fixation time
○ Can be hastened by: ___
OTHER CONSIDERATIONS DURING FIXATION:
* If autopsy materials are not able to be fixed as soon as possible these should be placed in
○ Mortuary Refrigerator kept at a temperature of __
o Undergo Arterial Embalming
Brain: __
Hollow Organs: __
Air Filled Lungs: __
Eyes: __
Hard Tissues (cervix, fibroids, hyperkeratotic skin, nails): washed out in running water and immersed in Tissue Softeners (ex. ___)
400-450 mOsm
0.25% Glutaraldehyde
2-6 hrs; 3hrs
1mm/hr
10-20
20:1!!
osmium tetroxide (5-10x)
at least 50x that of tissue
heating, agitation, microwave and vacuum
4°C
fix before grossing
pack in cotton soaked in fixative
tend to float, wrap in gauze
fix before grossing; inject with formol alc
Lendrum’s & Perenyi’s
FIXATIVE TYPES ACCDG TO COMPOSITION
A. ___: 1 component only
Ex. Aldehydes, Metallic Fixatives, Heat
B. ___: 2 or more components
FIXATIVE TYPES ACCDG TO ACTION:
A. ___: fixatives that permit the general microscopic study of tissue structures without altering the structural pattern and normal intercellular relationship of tissues
B. ___: preserves a specific part or element
1. ___: nucleus and chromatin material perservation; added with glacial acteic acid (increases affinity of nuclear chromatin); pH 4.6 or less
2. ___: cytoplams & organelle preservation; NO glacial acetic acid (it promotes swelling of membrane)l pH 4.6 or more
3. ___: specific chemical components
SIMPLE FIXATIVES
COMPOUND FIXATIVES
Microanatomical
Cytological
Nuclear
Cytoplasmic
Histochemical
10% Formol saline
10% neutral buffered saline
Heidenhain’s Susa
Formol Sublimate
Zenker’s
Bouin’s
Brasil’s
Microanatomical fixatives
Flemming’s
Carnoy’s
Bouin’s
Newcomer’s
Heidenhain’s Susa
nuclear fixatives
Flemming’s without HOAC
Kelly’s
Formalin with post chroming
Regaud’s
Orth’s
Cytoplasmic
10% Formol saline
Absolute ethanol
Acetone
Newcomer’s
Histochemical
ALDEHYDE FIXATIVES
A. ___ -gas produced from the oxidation of methanol
__ Formalin: concentrated stock solution
__ Formalin: routine concentration
○ Usually Buffered with PO4 buffer to pH 7 (less prone to formation of formalin pigments - brown pigment when acidic)
○ added with ___ (retards decomposition of formic acid; but no longer suitable for EM)
○ usual fixation time: ___
Advantages: Cheap, Readily Available, Easy to Prepare; Relatively Stable; Compatible with many Stains
Disadvantages: Fumes Irritating to Nose and Eyes; Solution is Irritating to Skin (allergic dermatitis)
- Prolonged Storage of 10% Formalin leads to formation of __; Remedy: ___
- Brown or Black Crystalline Precipitates (Acid Formaldehyde Hematein) on blood containing tissues (such as spleen) due to action of formic acid with blood
○ Remedy (Removal of Formalin Pigments)
■ ___: (70% ethanol & 28% ammonia water)
■ ___: (Hydrogen Peroxide & 28% ammonia water
■ Picric Acid Method (Saturated Alcoholic Picric Acid)
■ 1% KOH in 80% Alcohol
Formalin (Formaldehyde)
37-40%
10%
10% methanol
12-24 hrs
white precipitate (paraformaldehyde)
filtration or addition of 10% methanol
Kardasewitsch’s Method
Lillie’s Method
ALDEHYDE FIXATIVES
B. ___: Microanatomical Fixative
> Diluted with NaCl
> Fixation of CNS tissues and General Post Mortem Tissues for Histochemical Examination > Ideal for Silver Impregnation techniques
C. ___ (pH 7.0)
> Best Fixative for iron containing pigments and elastic fibers; BEST/RECOMMENDED ROUTINE FIXATIVE
> Inert to Lipids
> Longer to Prepare
D. ___
> contains mercury/mercuric chloride
> Excellent for stains like Sliver Reticulin Mtds
> No washing Out
> Fixes Lipids
10% Formol Saline
10% Neutral Buffered Formalin or PO4 Buffered Formalin
Formal Corrosive (Formol Sublimate)
ALDEHYDE FIXATIVES
E. ___
> has 95% ETOH with Picric acid and Glacial Acetic Acid
> Good for glycogen, microincineration techniques, sputum spx
> Fixes sputum
F. ___
> Chemical Composition: 2 formalin residues linked by 3 carbon chains
> Acts similarly to formalin
> 2.5% (Small Tx Fragments), 4% (Large Tx)
> Recommended for enzyme histochem, EM
>Widely used primary fixative for TEM
> Better preservation of cellular and fluid proteins More pleasant and less irritating but expensive
> Specimen Vial should be refrigerated
G. ___
> polymer of formalin in white powder form; 4%
> Use: thin and ultrathin sections for plastic embedding; EM
Gendre’s/Alcoholic Formalin/Alcoholic Bouin
Glutaraldehyde
Paraformaldehyde
METALLIC FIXATIVES
A. ___: most common metallic fixative
> Concentration: __; included in compound fixatives
> May produce black granular deposits except ___. Removal of black granular deposits can be done by __
o Addition of saturated iodine solution of 96% Alcohol & 5% sodium thiosulfate
> Penetrates and Hardens Tx rapidly
> Routine Fixative of Choice for Preservation of Cell Detail in Tx Photography
> Fixation of ___ and ___
Mercuric Chloride
5.7%
Heidenhain’s Susa; dezenkerization
hematopoietic and reticuloendothelial tissues
METALLIC FIXATIVES
1. ___: contains Glacial Acetic Acid
> Recommended for Small Pieces of Liver, Spleen, CT Fibers and Nuclei
> Recommended for Trichrome Staining
- ___: (AKA_) Contains Potassium Dichromate and Formalin
> Excellent Microanatomical Fixative of Pituitary Gland, BM and Blood containing Organs > Preserves Cytoplasmic Granules
> Produces BROWN pigments (remove using picric acid or NaOH) - ___: has TCA, Glacial HoAc, Formalin
> recommended for skin tumor biopsies - ___: has Anhydrous Na acetate
> for one marrow biopies, lymph nodes
Zenker’s
Zenker Formol; Helly’s/Kelly’s solution
Heidenhain’s Susa
B5 Fixative
B. Chromate Fixatives
Chromate Fixatives:
○ Concentration: ___ aqueous solutions
○ strong oxidizing agents and should not be combined with reducing agents
○ preserves ___
- ___: 3% aqueous solution
> preserves lipids and mitochondria at pH 4.5-5.2 cytoplasm, chromatin and chromosomes fixed - ___: (AKA: ___)
> chromatin, mitochondria, mitotic figures, Golgi bodies, RBC and colloid containing tissues - ___:
> for early degenerative processes and tissue necrosis demonstration of RICKETTSIA!!
> preserves myelin!
C. Lead Fixatives
4% aqueous solution and recommended for ____
Fixes Mucin also
1-2%
carbohydrates
Potassium Dichromate
Regaud’s; Mueller’s
Orth’s Fluid
~
acid mucoplysaccharides
___
Usually used in strong or saturated solutions; explosive when dry!
Chemically: ___
Major Disadvantage: yellowing of tissues
○ Remedy: Saturated Solution of Lithium Carbonate in 70% Alcohol then washed with water. The tissue is then placed in 70% ethanol followed by 5% Sodium Thiosulfate and washed with water
Uses:
> Excellent for Glycogen
> Can be used as a stain (yellow) and small tissue fragments can be seen
1. ___: recommended for embryos and pituitary biopsies
> excellent for preserving soft and delicate structures
> Preferred fixative for tissues to be stained by Masson’s trichrome stain
> NOT for kidney fixation
2. ___:
> has TCA
> better and less messy than Bouin’s > fixes glycogen
3. ___:
> for GI tract samples and for endocrine tissues
> less lysis than Bouin’s
> decalcifying property
PICRIC ACID FIXATIVES:
2,4,6 trinitrophenol
Bouin’s
Brasil’s Alcoholic Picroformol Fixative
Hollande’s Solution
____:
○ Usually incorporated in compound fixatives
○ Solidifies at 17°C
○ Precipitates Nucleoproteins, Chromatin Materials
○ Not for Cytoplasmic Fixation
___:
○ Rapidly denatures and Precipitates Proteins
○ Acts as a ___
○ Excellent for Glycogen!!!
○ Preserves Nuclear Stains but dissolves ___
1. ___
➤ for dry and wet smears (blood and bone marrow smears)
➤ Disadvantage: toxic when ingested
2. ___
➤ fixes touch preparations, Wright/Giemsa staining
3. ___
➤ simple fixative
➤ doesn’t fix glycogen
➤ useful for recovering DNA fragments for PCR
4. ___
➤ most rapid fixative
➤ Fixation time: ___
➤ contains absolute alcohol, chloroform and glacial acetic acid
➤ fixes and dehydrates at the same time
➤ recommended for chromosomes, lymph glands and urgent biopsies!!
➤ fixes Nissl granules (tigroid substance in rER) and Cytoplasmic Granules!!
5.
➤ recommended for mucopolysaccharides and nuclear proteins
➤ acts as both a nuclear and biochemical fixative
GLACIAL ACETIC ACID FIXATIVES
ALCOHOL FIXATIVES
fixative and dehydrating agent
fats and lipids
Methanol (100%)/Wood alcohol
Isopropyl Alcohol (95%)
Ethanol (70-100%)
Carnoy’s Fixative
1-3 hrs
Newcomer’s
___
Pale yellow powder that dissolves in water (6% at 20C)
Uses:
A. fix and stain unconjugated fats (stain fats black)
B. fixative for EM (secondary fixative after aldehyde)
Other Uses: Preserves mitochondria and Golgi Bodies
Disadvantage: expensive, inhibits hematoxylin; leads to corneal blindess!!!
- ___
> most common chrome-osmium acetic acid fixative
> excellent fixative for nuclear structures
> needs lesser amount of fixative - ___
> for cytoplasmic structures especially mitochondria
____
○ Precipitates proteins
○ Another purpose: Weak Decalcifying Agent also
○ Has a softening effect on dense tissues
___ (also a dehydrating agent)
○ Used at Ice Cold Temperature from ___
○ For Diffusible Enzymes such as Phosphatases and Lipases
○ For Fixing Brain Tissues: ___
OSMIUM TETROXIDE/Osmic acid
Flemming’s
Flemming’s without Acetic Acid
~
TCA Fixatives/Trichloroacetic Acid
ACETONE FIXATIVES
-5°C to -4°C
rabies
Fixatives for Enzyme Histochemistry
○ ___
○ ___
Fixatives for EM:
- osmium tetroxide
- glutaraldehyde
- paraformaldehyde
○ Optimum temperature for Fixation: ___
Fixative for Electron Histochemistry and Electron Immunocytochemistry:
1. Best: ___
2. Addition of Acrolein with glutaraldehyde or formaldehyde
Other Fixatives combined with Rapid Microwave Techniques:
> __: mixture of methanol and PEG; cost effective alternative to formalin Able to recover RNA, DNA, proteins for molecular analysis
○ 4% formalin or formol saline
○ Acetone or formalin for cryostat sections
4°C
Karnovsky’s Paraformaldehyde Glutaraldehyde
UMFIX
___
* Thermal Coagulation of Tissue Proteins
* For Frozen Tissue Sections and Preparation of Bacteriologic Smears
Microwave Technique:
- Physical agent similar to heat(oven)
- Increases movement of molecules and accelerate fixation, staining, decalcification, EM, and immunohistochemistry (antigen retrieval)
- Optimum temperature:___
- Can penetrate tissue with thickness of ___
HEAT FIXATION
45-55°C
10-15mm
FACTORS AFFECTING FIXATION
* Retarded by:
- Size and Thickness
- Presence of Mucus (remedy: __)
- Presence of Fat
- Presence of Blood (remedy: __)
- Cold Temperature
*Enhanced by:
- Thinner and small size of tissues
- Agitation - reduce overall processing time by ___
- Heat
Remedy:
wash with NSS
wash with NSS
30%
TERMS RELATED TO FIXATION
* ___: Placing an already fixed tissue into another fixative to:
- Facilitate and improve the demonstration of substances
- Special Staining
- Ensure further and complete hardening and preservation
- ___: secondary fixation using 2.5-3% Potassium Dichromate for 1 day to act as a ___
- Also known as ___
- ___: removal to excess fixative in order to improve staining and remove artifacts
- Tap Water - chromates, formalin, osmium tetroxide
- 50-70% Alcohol - excess alcohol/picric acid
- Alcoholic Iodine - excess mercury
TRANSPORT MEDIUM: ___ - for unfixed tissues (renal,skin, oral mucosa biopsies); refrigerated; not a fixative
Secondary Fixation
Post-Chromatization; mordant
post-modanting
Washing Out
Michel’s Solution
____
- Removal of Calcium or lime salts from bones or calcified tissues FOLLOWING __
- More concentrated acid solutions decalcify more rapidly but may destroy tissue - Ratio: ___
- Heat and Agitation hastens decalcification
- __ the tissue in the decalcifying fluid hastens decalcification
- Duration: ___
Types of Decalcifying Agents
1. Acids
2. Chelating Agents
3. Ion Exchange Resins
4. Electrophoresis
DECALCIFICATION
fixation
20:1
Suspending
1-2 days