PART 3 - HP - PT -fr Sir Ed Flashcards by Patricia Baltazar

Four Major Groups of Fixatives

It act by cross-linking proteins

Aldehydes (formaldehyde, glutaraldehyde)

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Four Major Groups of Fixatives

act by cross-linking proteins

Oxidizing agents (osmium tetroxide, potassium permanganate)

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Four Major Groups of Fixatives

act by denaturing proteins

Alcohol-based fixatives (methanol, ethanol, acetic acid)

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Four Major Groups of Fixatives

act by forming insoluble metallic precipitates

Metallic fixatives (mercuric chloride and picric acid)

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Aldehyde Fixatives

-Best for CNS and Gen. post-mortem tissues, ideal for silver impregnation

10% Formol-Saline

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Aldehyde Fixatives

Best Gen. tissue fixative; Frozen section, Iron and elastic fibers; Immunohistochemistry and interphase FISH

10% Neutral-Buffered Formalin

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Aldehyde Fixatives

for Immunohistochemistry

Zinc Formalin (unbuffered)

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Aldehyde Fixatives

for Routine post-mortem tissues, Silver Reticulum methods; Neutral fats and
phospholipids

Formol-Corrosive (F-Sublimate)

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Aldehyde Fixatives

EM; Immunocytochemical analysis; Paraffin embedding and sectioning

Paraformaldehyde

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Aldehyde Fixatives

EM; Resin embedding and sectioning

Karnovsky’s Fixative

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Aldehyde Fixatives

Electron Microscopy

Acrolein

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Aldehyde Fixatives

Lipids (frozen section); Fixation & decalcification of calcium-rich tissues

Formol-calcium (Baker’s)

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Aldehyde Fixatives

Sputum cytology

Gendre’s

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Aldehyde Fixatives

for Phospholipids

Lillie’s (Calcium acetate formalin)

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Aldehyde Fixatives

For Nervous tissue (astrocytes)

Cajal’s Formol-ammonium bromide

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Aldehyde Fixatives

Wet and dry smears, blood smears, bone marrow tissues and cell cultures; Diluent
in Wright’s stain

Methyl Alcohol (100%)

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Aldehyde Fixatives

Fixing touch preparations (impression smears)

Isopropyl Alcohol (95%

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Aldehyde Fixatives

Histochemistry especially enzyme studies; Sodium urate crystals in patients with
gout; DNA fragments (PCR)

Ethyl Alcohol (70-100%)

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Aldehyde Fixatives

(most rapid fixative)

Chromosomes, lymph glands, urgent biopsies; Brain tissues for rabies diagnosis
(Negri bodies); Nissl and cytoplasmic granules

Carnoy’s Fixative (most rapid)

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Aldehyde Fixatives

Frozen sections and smears; Nucleic acids

Clarke’s Solution

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Aldehyde Fixatives

Fixation or post-fixation of large fatty specimens (breast); Lymph nodes detection

Alcoholic Formalin

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Aldehyde Fixatives

Diagnostic cryostat sections

Formol-Acetic Alcohol

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Aldehyde Fixatives

Sputum; Frozen sections; Immunoperoxidase studies and EM; Glycogen and
Micro-incineration technique

Gendre’s Fixative

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Aldehyde Fixatives

Mucopolysaccharides and nuclear proteins

Newcomer’s Fluid

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Mercuric chloride Fixatives Tissue photography; Renal tissues, fibrin, CT and muscles; Metachromatic staining and Trichrome staining; Hematopoietic & RES

Mercuric chloride

Mercuric chloride Fixatives Good general fixative; Recommended for PTAH & Trichrome staining; Congested specimens (lung, heart and blood vessels)

Zenker's Solution

Mercuric chloride Fixatives Blood-containing organs (pituitary gland, BM, liver and spleen); Extramedullary hematopoiesis and intercalated discs of cardiac muscle

Zenker-Formol (Helly’s) Solution

Mercuric chloride Fixatives BM biopsies (hematopoietic tissues); Immunohistochemical staining

Lillie’s B-5 Fixative

Mercuric chloride Fixatives Tumor biopsies (skin)

Heidenhain's Susa Solution

Mercuric chloride Fixatives Wet smears for cytologic examinations

Schaudinn's (Sublimated alcohol)

Mercuric chloride Fixatives Lipids and proteins; Nervous tissue and brain; Nuclear preservation

Ohlmacher's Solution

Mercuric chloride Fixatives Lipids and fatty tissues (liver and adipose); Nuclear preservation

Carnoy-Lebrun Solution

Osmium tetroxide Fixatives Nuclear structures (Chromosomes); Fixes fats

Flemming's Solution

Osmium tetroxide Fixatives Cytoplasmic structures (mitochondria)

Flemming's w/o Acetic Acid

Chromate Fixatives Precipitates all proteins and adequately preserves carbohydrates

Chromic Acid

Chromate Fixatives Chromatin, mitochondria, mitotic figures, golgi bodies, RBCs and colloidcontaining tissues

Regaud’s (Muller's) Fluid

Chromate Fixatives Study of early degenerative processes and tissue necrosis; Rickettsia and other bacteria

Orth's Fluid

Chromate Fixatives Preserves mitochondria, fixes lipids

Potassium Dichromate

Picric acid Fixatives -Embryos and pituitary biopsies; GIT biopsies, animal embryos and endocrine gland tissue -GREEN GREGORIOS: Preserving soft and delicate structures (endometrial curettings); Fragmentary biopsies; Masson’s trichrome; Not suitable for fixing kidney structures, lipid and mucus

Bouin's Solution

Picric acid Fixatives GIT specimens and endocrine tissues; Has decalcifying properties

Hollande’s Solution

Picric acid Fixatives -Glycogen and other carbohydrates -BLACK GREGORIOS: Preserving soft and delicate structures (endometrial curettings); Fragmentary biopsies; Masson’s trichrome; Not suitable for fixing kidney structures, lipid and mucus

Gendre’s Solution

Picric acid Fixatives Best routine fixative for glycogen

Brasil's Alcoholic Picroformol

Other Fixatives Nucleoproteins (nuclei); Chromosomes and chromatin materials (nuclear components); Destroys mitochondria and Golgi bodies

Glacial acetic acid (HAc)

Other Fixatives Acid mucopolysaccharides and CT mucin

Lead Fixatives

Other Fixatives Proteins and nucleic acids; Weak decalcifying agent

Trichloroacetic Acid (TCA)

Other Fixatives Water diffusible enzymes (Lipases, Phosphatases); Brain tissues for rabies diagnosis (Negri bodies); Solvent in freeze-substitution tech

Acetone

Other Fixatives Transport medium of fresh unfixed tissues; NOT a fixative

Michel’s Solution

Fixative Recommend for Immunohistochemical techniques, cell smears, nucleic acids, CNS: Formaldehyde

Formaldehyde

Fixative Recommended for chromaffin tissues, adrenal medulla and mitochondria

Chromate

Fixative Recommended for Connective tissues and glycogen; Histones & basic proteins; Biogenic and polypeptide hormones Immunostaining; Fragmentary biopsies:

Picric acid

Fixative Good fixative and excellent stain for lipids:

Osmium tetroxide

Nuclear and histochemical fixative

Newcomer’s fluid

Microanatomical and histochemical

10% Formol saline

Microanatomical and nuclear:

Heidenhain’s susa

Microanatomical and cytoplasmic

Zenker-formol (Helly’s)

10% NBF Composition

✓ 37-40% formaldehyde - 100 mL (10% = equivalent to 3.7-4% formaldehyde) ✓ DW - 900 mL ✓ Sodium phosphate, monobasic - 4 g ✓ Sodium phosphate, dibasic (anhydrous) - 6.5 g *anhydrous – no water / water-free

Bouin’s Fixative Composition

✓ 2.1% Picric acid saturated aqueous solution - 75 mL ✓ 40% formaldehyde - 25 mL ✓ Glacial Acetic acid - 5 mL

Most commonly used fixative in histology:

Formaldehyde

Most widely used fixative for routine histology:

10% NBF

Used to slow down decomposition if the tissue needs to be photographed and cannot be fixed immediately

Refrigeration

Used to prevent formation of dark brown artifact pigment granules (hematin) when using formalin fixatives:

✓ Add buffer - Sat. alcoholic Picric acid - Others: Acidified potassium phosphate buffer, Sodium acetate buffer and Citrate buffer ✓ Add Alcoholic KOH (1% KOH in 80% alcohol)

Fixative and decalcifying agent

Trichloroacetic acid Picric acid Chromic acid

Fixative and dehydrating agent:

Alcohol (Methanol, Carnoy’s, Gendre’s) Acetone

Fixative and stain:

Picric acid, Osmium tetroxide

Decalcifying agent and tissue softener:

Perenyi’s fluid

Dehydrating agent and clearing agent (universal rgt):

Tetrahydrofuran Dioxane, 3° Butanol Oil of Bergamot

May cause excessive hardening or brittleness of tissues:

✓ Prolonged fixation ✓ Prolonged dehydration ✓ Prolonged clearing ✓ Prolonged infiltration ✓ Prolonged embedding (overheating)

Airholes found in the tissue during trimming is due to:

Incomplete infiltration

Prolonged dehydration in the higher grades of alcohol will render the specimen:

Hard and brittle

Makes the tissue opaque and difficult to cut due the presence of alcohol:

Incomplete clearing

The most common (routine) and most rapid decalcifying agent used so far:

Nitric acid

Best for cellular preservation and staining; Recommended for routine decalcification of post-mortem research tissues:

Formic acid

Recommended for Surface decalcification of tissue blocks if used in 1% solution with 70% alcohol:

Hydrochloric acid

Permits good nuclear staining; Does not require washing out; Not recommended for urgent examinations (very slow acting):

Trichloroacetic acid

A good clearing agent must be ____________ with dehydrating agent (alcohol), melted paraffin wax and mounting medium.

Miscible

An excellent and true clearing agent; most rapid:

Xylene

Substitute for xylene or benzene:

Toluene

It is recommended for tough (skin, fibroid and decalcified tissues) and large tissue specimens;

Chloroform

Clearing agent Rapid acting, recommended for urgent biopsies and routine purposes

Benzene

Dehydrates and clears at the same time since it is miscible in both water and paraffin:

Tetrahydrofuran

Recommended for CNS tissues and cytological studies (esp. Smooth muscles and skin):

Cedarwood oil

Clears both Paraffin and Celloidin sections; Quality is not always uniform and good and is extremely slow

Cedarwood oil

Properties are very similar to chloroform but it is cheaper; Toxic on prolonged exposure:

Carbon tetrachloride

Slow-acting clearing agents that can be used when double embedding techniques are required:

Methyl-benzoate/Methyl-salicylate

The clearing agent that becomes milky on prolonged storage and its quality is not always good and uniform:

Cedarwood oil

The clearing agent that becomes milky when dehydration is not complete:

Xylene

▪ Infiltrating and embedding media:

✓ Paraffin ✓ Paraffin substitutes ✓ Celloidin ✓ Gelatin ✓ Resin

The simplest, most common, and by far the best embedding medium for routine use:

Paraffin wax

The impregnation method used for delicate specimens and frozen tissue sections because it prevents fragmentation of tough and friable tissue:

Gelatin Impregnation

Specimens with large cavities or hollow spaces:

Celloidin wax impregnation

EM; Hard tissues (undecalcified bone); renal and BM biopsies:

Resin/Plastic Impregnation

Preferred for processing of whole eye sections. Material embedded with the dry method can be cut without alcohol due to the presence of the cedarwood oil in the block.

DRY Celloidin Method

equal parts of chloroform and cedarwood oil, what mixture it is?

Gilson’s mixture

PART 3 - HP - PT -fr Sir Ed Flashcards

(96 cards)