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137 Cards in this Set
- Front
- Back
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Acetic acid:
Purpose/tissue |
Sometimes added to counteract the shrinking affect of another reagent. Not used alone.
To precipitate and preserve nucleoproteins; notable ability to fix nuclei |
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Acetic acid:
Safety concerns? |
PEL of 10 ppm
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Acetic acid:
Fixation times? |
Rapid rate of penetration; leaves tissues soft
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Formaldehyde:
Purpose/tissue |
Used because of minimal shrinkage of tissues
Ability to allow more special stains than any other fixative |
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Formaldehyde:
Safety concerns? |
PEL 0.75 ppm
Possible carcinogen |
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Formaldehyde:
Fixation times |
Penetrates very quickly, but fixes very slowly
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Formaldehyde:
Special information |
Can leave slides with formalin pigment when pH < 6.0.
Pigment can be prevented and removed. |
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Glutaraldehyde:
Purpose/tissue |
Used for the fixation of specimens for electron microscopy
Preserves ultrastructure better than any of the aldehydes. |
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Glutaraldehyde:
Safety concerns |
Possible carcinogen, handle like formaldehyde
PEL 0.75 ppm |
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Glutaraldehyde:
Special information |
Tends to overharden tissues
Must be kept in frozen vials; breaks down with exposure to oxygen |
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Mercuric chloride:
Purpose/tissue |
Used in compound fixatives
Very powerful protein coagulant; enhances staining by leaving the tissue very receptive to dyes |
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Mercuric chloride:
Safety concerns |
PPM of .5-.7
Very toxic, very corrosive. Requires cradle-to-grave tracking. |
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Mercuric chloride:
Fixation times |
Penetrates poorly and causes shrinkage
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Mercuric chloride:
Special information |
When in tissues, inhibits freezing (makes frozen sectioning difficult).
Fixation pigment is formed but cannot be prevented, only removed. |
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Osmium tetroxide:
Purpose/tissue |
Used for the fixation of specimens for electron microscopy.
Used for the preservation of lipids. Chemically combines with lipids to make the insoluble. |
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Osmium tetroxide:
Safety concerns |
Very dangerous: fixes nasal mucosa and eyes.
Must use under the hood. OSHA TWA is 0.002 ppm, vaporizes readily. |
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Osmium tetroxide:
Special information |
Used after an aldehyde fixative.
Can be used for paraffin processing of lipids. |
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Another name for the pigment left by formaldehyde
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Black acid hematin
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Picric acid:
Purpose/tissue |
Constituent of fixatives for glycogen
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Picric acid: safety information
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Explosive when dehydrated. Must keep moist even in the cap of the bottle. OSHA TWA 10 ppm
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Picric acid: fixation times
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Very slow rate of penetration and fixation
Gives tissue a very good soft consistency |
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Picric acid: special information
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A fixative and a stain (yellow)
Strong acid that destroys nucleic acids, so if staining for DNA or RNA, avoid picric acid Decalcifies tissue to a small degree like breast bx, cannot be used as routine decalcifier |
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Potassium dichromate
Purpose/tissue |
Preserves mitochondria, but dissolves DNA
Chromium will attach to some lipids, rendering them insoluble but not to the degree of osmium tetroxide |
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Potassium dichromate
Safety concerns |
Requires cradle to grave tracking
TWA is 0.05 ppm Carcinogen, corrosive to skin and mucous membranes |
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Potassium dichromate
Fixation times |
Slow rate of penetration if pH <3.5
Rapid rate of penetration if pH >3.5 Gives tissue a soft consistency |
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Potassium dichromate
Special information |
Pigment formation can occur. Pigment removed with 1% HCL and 70% alcohol
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Zinc salts
Tissue/purpose |
Replacement for mercury
Preserves tissue antigenicity Superior nuclear detail |
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Zinc salts
Safety concerns |
None
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Zinc salts
Rate of fixation |
Slow rate of penetration and fixation
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Zinc salts
Special information |
Combined with formalin for post-fixation on the processor
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B-5 stock solution
Tissue/purpose |
Fixative of hematopoietic and lymphoreticular tissues because it demonstrates beautiful nuclear detail
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B-5 stock solution
Safety concerns |
Requires cradle to grave tracking
PEL of 0.7 ppm |
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B-5 stock solution
Rate of fixation |
Moderate rate of penetration and fixation
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B-5 stock solution
Special information |
Cannot store tissues in this fixative, they will eventually be destroyed
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Zenker and Helly stock solution
Tissue/purpose |
Used as the stock solution for Zenker's solution and Helly's solution
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Zenker and Helly stock solution
Safety concerns |
Requires cradle to grave tracking
PEL of 0.7 ppm |
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Zenker and Helly stock solution
Rate of fixation |
Moderate rate of penetration and fixation
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Zenker and Helly stock solution
Special information |
Removal of mercury pigment is necessary. Cannot be stored over 24 hours or overhardening will occur
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10% aqueous formalin
Tissue/purpose |
General fixative
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10% aqueous formalin
Safety concerns |
PEL of 0.75 ppm
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10% aqueous formalin
Rate of fixation |
Fast rate of penetration and slow rate of fixation
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10% aqueous formalin
Special information |
Very hypotonic
May produce formalin pigment |
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10% formalin saline
Purpose/tissue |
General fixative
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10% formalin solution
Safety concerns |
PEL of 0.75 ppm
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10% formalin saline
Rate of fixation |
Fast rate of penetration, slow rate of fixation
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10% formalin saline
Special information |
Isotonic
May produce formalin pigment |
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Calcium formalin
Purpose/tissue |
Fixation and preservation of phospholipids in tissues
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Calcium formalin
Safety info |
PEL of 0.75 ppm
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Calcium formalin
Rate of fixation |
Fast rate of penetration, slow rate of fixation
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Calcium formalin
Special info |
Can leave formalin pigment
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Formalin ammonium bromide
Tissue/purpose |
Recommended only for tissue of the CNS
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Formalin ammonium bromide
Safety |
PEL of 0.75 ppm
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Formalin ammonium bromide
Rate of fixation |
Fast rate of penetration, slow rate of fixation
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Formalin ammonium bromide
Special info |
Solution is very acidic
Lyses RBCs Causes nuclei to give a direct positive Schiff reaction due to the Feulgen hydrolysis during fixation |
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Acetate formalin
Tissue/purpose |
General fixative that doesn't require a buffer
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Acetate formalin
Safety info |
PEL of 0.75 ppm
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Acetate formalin
Rate of fixation |
Fast rate of penetration, slow rate of fixation
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Acetate formalin
Special info |
Pseudocalcification of tissue can be caused and may be difficult to distinguish from true calcification
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10% neutralized formalin
Tissue/purpose |
General fixative
Not recommended because solution become acidic after withdrawl from the storage bottle |
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10% neutralized formalin
Safety info |
PEL of 0.75 ppm
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10% neutralized formalin
Rate of fixation |
Fast rate of penetration, slow rate of fixation
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10% neutralized formalin
Special info |
Can cause formalin pigment
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10% neutral buffered formalin
Tissue/purpose |
General fixative recommended for routine fixation
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10% neutral buffered formalin
Safety info |
PEL of 0.75 ppm
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10% neutral buffered formalin
Rate of fixation |
Moderate rate of penetration and fixation
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10% neutral buffered formalin
Special info |
pH of 6.8
Hypotonic |
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Modified Millonig formalin
Purpose/tissue |
Dual purpose fixative, allowing electron microscopy on stored tissue
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Modified Millonig formalin:
Safety info |
PEL of 0.75 ppm
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Modified Millonig formalin
Rate of fixation |
Fast rate of penetration, slow rate of fixation
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Modified Millonig formalin
Special info |
pH of 7.2-7.4
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Alcoholic formalin
Tissue/purpose |
Useful as a fixative on the tissue processors and as a general purpose fixative. Dehydrates as it fixes.
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Alcoholic formalin
Safety info |
PEL of 0.75 ppm
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Alcoholic formalin
Rate of fixation |
Rapid rate of penetration and fixation
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Alcoholic formalin
Special info |
Tissue may be stored indefinitely in this solution
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B-5 solution
Tissue/purpose |
Fixative of hematopoietic and lymphoreticular tissues
Demonstrates beautiful nuclear detail |
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B-5 solution
Safety info |
Cradle to grave precautions for mercuric chloride
PEL of 0.5-0.7 ppm |
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B-5 solution
Rate of fixation |
Moderate rate of penetration and fixation
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B-5 solution
Special info |
After fixation, wet tissue must be stored in a storage solution, usually 70% alcohol.
Mercury pigment will form and must be removed. |
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Bouin solution
Tissue/purpose |
Excellent for tissue that will undergo trichrome staining and for preserving structures with soft and delicate textures.
Brilliant nuclear and cytoplasmic staining with H&E stains. Tissue sections easily. Excellent for biopsy specimens of the GI tract. Tissue of the endocrine system is well-fixed. Many antibodies react well with tissue fixed in this solution. |
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Bouin solution
Safety info |
PEL of 0.75 ppm
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Bouin solution
Rate of fixation |
Rapid rate of penetration and moderate rate of fixation.
Swelling effect of acetic acid balanced by shrinking effect of picric acid. Hardening effect of formaldehyde counteracted by soft fixation of picric acid. |
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Bouin solution
Special info |
Yellow stain from picric acid must be removed before processing by: washing with 50-70% alcohol or 70% alcohol with lithium carbonate.
RBCs are lysed. Cannot be used for the preservation of tissue that must be examined ultrastructurally (EM) or when nucleic acids must be demonstrated. |
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Gendre solution
Tissue/purpose |
Excellent for the preservation of some carbohydrates, esp. glycogen
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Gendre solution
Safety info |
PEL of 0.75 ppm
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Gendre solution
Rate of fixation |
Rapid rate of penetration and fixation
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Gendre solution
Special info |
Yellow color must be removed by washing with 50-70% alcohol or 70% alcohol with lithium carbonate
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Hollande solution
Tissue/purpose |
Primary fixative for GI and prostate biopsies.
Good for bone marrow biopsies. Solution stabilizes RBC membranes and the granules of eosinophils and endocrine cells. |
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Hollande solution
Safety info |
PEL of 0.75 ppm
Carcinogen |
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Hollande solution
Special info |
Can be stained successfully with most special stains.
Must be washed out before the specimen is placed in a phosphate-buffered formalin solution on the tissue processor. |
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Zenker working solution
Tissue/purpose |
Great nuclear fixative and is used as a mordant in some staining procedures.
Best of all fixatives but is hazardous. |
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Zenker working solution
Safety info |
Cradle to grave tracking due to potassium dichromate and mercury.
PEL of 0.05 ppm |
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Zenker working solution
Rate of fixation |
Moderate rate of fixation
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Zenker working solution
Special info |
Lyses RBCs
Removal of mercury pigment is necessary Tissue cannot be stored over 24 hrs or overhardening will occur. Wash well in running water. Remaining wet tissue must be stored in 70-80% alcohol solution. |
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Helly working solution
Tissue/purpose |
Preserves RBCs
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Helly working solution
Safety info |
Cradle to grave tracking for potassium dichromate and mercury
PEL of 0.05 ppm |
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Helly working solution
Rate of fixation |
Moderate rate of penetration
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Helly working solution
Special info |
Preserves RBCs
Removal of mercury pigment necessary Tissue cannot be stored over 24 hours or overhardening will occur. Wash well in running water, remaining wet tissue must be stored in 70-80% alcohol solution |
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Orth solution
Tissue/purpose |
Used for demonstration of chromaffin (chromate-loving) granules in the cytoplasm of the adrenal medulla
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Orth solution
Safety info |
Cradle-to-grave tracking
Carcinogen 0.05 ppm |
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Orth solution
Rate of fixation |
Fairly rapid rate of penetration
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Orth solution
Special info |
Tissue must be washed after fixation
Time of fixation must be controlled Remaining wet tissue must be stored in 70-80% alcohol Intense pH of 5-6 |
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Zamboni solution
AKA |
PAF or buffered picric acid formaldehyde
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Zamboni solution
Tissue/purpose |
Good general purpose fixative.
Allows secondary fixation with osmium and preserved morphology accurately Preferred by some as primary fixative for electron microscopy |
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Zamboni solution
Safety info |
PEL of 0.75 ppm
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Zamboni solution
Rate of fixation |
Slow rate of fixation
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Zamboni solution
Special info |
pH of 7.3
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Alcohol zinc formalin
Purpose/tissue |
Recommended as a post-fixative solution following fixation with neutral buffered formalin.
Antigenicity is enhanced and nuclear detail is improved |
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Alcohol zinc formalin
Safety info |
Corrosive.
PEL of 0.75 ppm |
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Alcohol zinc formalin
Rate of fixation |
Very rapid fixation.
Fixes 1.5x faster than the aqueous solutions. Alcoholic solutions are recommended if 6-8 hours cannot be allotted for fixation. |
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Alcohol zinc formalin
Special info |
Alcohol solutions better for fatty tissues
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Unbuffered aqueous zinc formalin
Tissue/purpose |
General fixative
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Unbuffered aqueous zinc formalin
Safety info |
PEL of 0.75 ppm
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Unbuffered aqueous zinc formalin
Rate of fixation |
Moderate rate of fixation
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Unbuffered aqueous zinc formalin
Special info |
Formalin pigment can be formed by this solution.
If zinc formalin is to be followed by a neutral fixative such as phosphate buffered formalin, the tissue must be washed between reagents, as a precipitate can form on the tissue. |
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Carnoy solution
Purpose/tissue |
Preserves glycogen and exhibits good nuclear preservation
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Carnoy solution
Safety info |
Toxic substance
PEL of 10 ppm |
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Carnoy solution
Rate of fixation |
Very rapid rate of penetration.
Fixation should not be prolonged more than 4 hours |
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Carnoy solution
Special info |
Causes shrinkage and hardening of tissues
RBCs are lysed |
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Michel transport medium
Purpose/tissue |
Acts as a holding solution for long-distance travel of the tissue
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Michel transport medium
Rate of fixation |
Used as a holding solution
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Michel transport medium
Special info |
Important to keep a pH of 7.0 to 7.2 because a lower pH could cause variable results
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PBS buffer stock solution's working solution is...
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PBS 10% sucrose solution
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PBS 10% sucrose solution
Tissue/purpose |
Acts as a holding solution for long-distance travel of the tissue
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PBS 10% sucrose solution
Special info |
Tissue for immune complex deposit studies can be stored up to 2 weeks w/o effecting immunofluorescent or immunoperoxidase studies
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Methyl alcohol
Tissue/purpose |
Used frequently as a fixative for touch preparations and blood smears
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Methyl alcohol
Safety info |
Flammable
200 ppm |
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Methyl alcohol
Rate of fixation |
Very rapid acting fixative
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Methy alcohol
Special info |
Dissolves fats
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Ethyl alcohol
Tissue/purpose |
Preserves glycogen and urate crystals
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Ethyl alcohol
Safety info |
Flammable
1000 ppm |
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Ethyl alcohol
Special info |
Dissolves fats, overhardens tissue, shrinks tissue
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Acetone
Tissue/purpose |
Frequently used on frozen sections of tissues to be stained for cell surface antigens by IHC technique.
Used as a fixative for brain tissues when subsequent staining is for rabies diagnosis. |
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Acetone
Safety info |
PEL is 250 ppm
Highly flammable |
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Acetone
Rate of fixation |
Very rapid fixation
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Acetone
Special info |
Causes extreme tissue shrinkage, distortion, and overhardening
Recommended only for preservation of special tissue components |
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Lugol iodine solution
Tissue/purpose |
Removal of mercury pigment
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Lugol iodine solution
Special info |
Place the iodine and the potassium iodide in approx. 20 mL of DW and mix until dissolved.
Add the remaining water and mix well. |
