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65 Cards in this Set
- Front
- Back
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Art and science perform by medtech to produce good quality tissue section that will enable the pathologist to come up with accurate diagnosis |
Histopathologic techniques |
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Types of specimen submitted |
Biopsy Autopsy |
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Pre analytical factors |
Warm schemia Cold schemia |
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What is warm schemia |
Lac of blood supply after romoval of tissue |
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What is cold schemia |
Lack of oxygen after removal of tissue |
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Examples of specimen excluded from mandatory exam |
Foreskin from circumcision Lopo suction |
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Gross exam describing the ff: |
Dimension(size)-rounded off to the nearest 1cm Color Weight(the most important) rounded off to the nearest 0.1gram |
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Not all organ should be disected like |
Varicose vein Nasal bone from rhinoplasty Accessory digits |
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Primary purpose of fixatives |
Preserves tissue |
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2ndary purpose of fixation |
To harden the tissue to fascilitate cutting into thin slices |
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Most critical and initial important step in tissue processing |
Fixation |
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2 mechanism involve in fixation |
Additive and non additive fixation |
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When the fixative becomes part of the tissue it is called |
Additive fixation |
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It is an automatic tissue processor that can do fixation, dehydration, clearing and infiltration |
Autotechnicon |
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Commonly used fixative |
10% formalin |
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Acts similar to formaldehyde but usually use for EM |
3% Glutaraldehyde |
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Duration of fixation |
6 hours minimum 48 hrs maximum |
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Duration of fixation in EM |
3 hrs |
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Tissue must be distibuted to fixatives within |
20 to 30mins |
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Rememedy when the tissue is brain |
Intravascular perfusion(washing out of blood using ringer's lactate) |
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Remedy when the tissue is covered by blood and mucus |
Wash with nss |
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Remedy for fatty tissue |
Cut fatty tissue thinly |
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Penetration rate of a formalin |
1mm/hr |
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Factors you need to consider good choice fixative |
Urgency of the case or need for immediate exam
Types of tissue to be process Ex. Liver-zenker's Pituitary-bouins
Type of tissue structure to be studied Rickettsial/bacteria- orth's fluid Glycogen- brasils
Staining technique to be applied Ex. Bouin's is not for feulgens Newcomers is for feulgens
Type of section to be made whether serial or individual |
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Wrong choice of fixative can lead to |
Removing of important substance of the tissue |
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Effects of fixative in general |
-Harden the tissue -Prevent the tissue from decomposition -reduces risk of infection -it will act as a mordant -increase optical differentiation of cells and tissue making it more visible to microscope -it will act as a mordant |
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Char of a good fixatives |
-Fast reacting -Doesnt cause excessivg shrinkage -It must harden the tissue -Should inhibit bacterial decomposition -Cheap and easy to prepare |
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Types of fixation |
Physical method Chemical method |
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Physical methods |
Heat fixation Microwave Freeze-drying |
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Chemical methods |
Coagulant fixatives Cross-linking fixatives/non coagulant Compound fixatives |
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What is coagulant fixatives |
Maintains cellular structure and tissue morpholgy at light microscopic level Poor preservation of mitochondria and secretory granules |
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Example of coagulant fixatives |
Alcohol(ethanol and methanol) Acetone Picric acid Tricholoro acetic acid |
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Cross linking fixatives |
Glutaraldehyde Formaldehyde Aldehyde(choral hydrate, glyoxal) |
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Useful for fatty tissues like breast |
Alcoholic formalin |
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Types of fixation according to composition |
Simple Compound |
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Simple fixatives |
1.aldehydes a. Gulataraldehyde b. Fomaldehyde c. TCA d. Glacial acetic acid 2. Metallic fixatives a. Mercuric chloride b. Chromate fixatives Potassium dichromate Chromic acid c. Lead fixatives Picric acid Acetone Alcohol Acetic acid Osmium tatroxide d. Heat |
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Are those thay are made up of two or more fixatives |
Compound fixatives(alcholic formalin) |
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Types of fixative according to action |
Microanatomical Histochemical cytological fixatives |
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Are those that preserve specific parts and particular microscopic elements of cell itself |
Cytological fixatives |
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Are those that permit the general microscopic study of tissue structures without altering the structural pattern |
Microanatomical fixtvs |
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Are those preserve that chemical substance of cells and tissue |
Histochemicak fixatives |
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Microanatomical fixatives |
10% formol saline 10%neutral buffered formalin Heidenhein's susa Bouin's Brasil's Zenker formol(helly's) Zenker's solution Formol sublimate(corrosive) |
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Cytological fxtvs |
Nuclear fxtvs Cytoplasmic fxtvs |
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Nuclear fxtvs |
FCBHN Flemming's w/ GCA Carnoy's Bouin's Heidenhein's Newcomers |
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Ethanol, methanol and carnoy's |
Commonly used fixatives for nucleic acid |
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Appears to give most usable DNA fragments for polymerase chain reaction PCR |
Ethanol |
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Never contains acid which destroy mitochondria and golgi bodies |
Cytoplasmic fxtvs |
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pH of nuclear fxtvs |
Below 4.6pH |
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pH of Cytoplasmic fxtvs |
Above 4.6pH |
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Ex. Of cytoplasmic fxtvs |
Formalin with post chroming Flemmings without GCA Orth's fluid Regaud's/moller's fluid Kelly's fluid |
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Ex. Of histochemical |
10% formol saline-enzymes Acetone-lipases, phospatases Absolute ethyl alcohol- Newcomers-mucopolysaccharides |
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Types of fixative according to composition |
A.silmple fxtvs B. Compound fxtvs |
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Simple fxtvs |
1.aldehydes 2.metallic fxtvs 3.heat |
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Simple fxtvs of Aldehydes |
Formaldehydes Glutaraldehyde Glacial acetic acid Trichloroacetic acid |
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Simple fxtvs of metallic |
A. Mercuric chloride B. Chromate fxtvs Potassium dichromate Chromic acid C.lead Picric acid Acetic acid Acetone Alchohol Osmium tetroxide(osmic D. Heat |
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Are made of only one component substance |
Simple fxtvs |
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Are those that are made of two or more fxtvs which have been added together to obtain the optimal combinatiom |
Compound fxtvs Ex. Alcohol formalin |
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Fixtvs according to action |
Microanatomical Cytological Histochemical |
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Are those that permit the general microscopic study of tissue structures without altering the structural pattern |
Microanatomical |
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Those that preserve specific parts and particular microscopic elements of the cell itself |
Cytological |
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Thise that preserve the chemical constituents of cells and txs |
Histochemical |
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Ex of microanatomical |
1010 ZZ BB FH 10% neutral buffered formalin 10% formol saline Zenker's fluid Zenker-formol fluid Bouin's fluid Brasil's fluid Formol sublimate( corossive) Heidenhain's susa |
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Cytological fxtvs must preseve organelles in both |
Nucleus and cytoplasm |
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Nuclear ftvs |
FCBNH Flemming's fluid(w/ acetic) Carnoy's Bouin's Newcomer Heidenhain's susu |
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______Those that preseve nuclear structures(e.g. chromosome) in particular. That usually contain_______with the pH of |
Nuclear fxtvs Glacial acetic acid Less than 4.6pH |
