FIXATIVES Flashcards
aldehydes fixatives
formaldehyde
glutaraldehydes
metallic fixatives
mercuric chloride
chromate fixatives
lead fixatives
heat
simple fixatives
aldehydes
metallic fixatives
microanatomical fixatives
- 10% Formol Saline
- 10% Neutral Buffered Formalin
- Heidenhein’s susa
- Zenker’s solution
- Zenker’s formol (Helly’ssolution)
- Bouin’s solution
- Brasil soln
cytological fixatives
nuclear
1. Flemming’s Fluid
2. Carnoy’s Fluid
3. Bouin’s Fluid
4. Newcomer’s Fluid
5. Heidenhain susa
cytoplasmic
1. Flemming’s Fluid with out acetic acid
2. Helly’s Fluid
3. Regaud’s Fluid (Muller’sfluid)
4. Orth’s Fluid
histochemical fixatives
- Formol Saline10%
- Absolute Ethyl Alcohol
- Acetone.
- Newcomer’s Fluid
usual fixation time of formaldehyde
24 hrs
percent of formaldehyde that is usually used is
10%
formaldehyde
a gas produced by the oxidation of
methyl alcohol
formaldehyde is buffered with pH ___ phosphate buffer
7
chear, readility available, easy to prep and relatively stable
formaldehyde
compatible with most stains
formaldehye
preserves fats, glycogen, mucin
formaldehyde
allows tissue enzymes to be studied because it does not precipitate proteins
formaldehyde
recommended for nervous tissue preservation
formaldehyde
Maycause
sinusitis,allergic
rhinitis,excessive
lacrimationor
allergicdermatitis
formaldehye
a soft fixative and does not harden some cytoplasmic structures adequately enough for paraffin
formaldehyde
recommended for COLORED TISSUE photography
formaldehyde
tolerant fixative used for mailing specimen
formaldehyde
recommended for fixation of central nervous system and general post mortem tissues for histochemical examination
10% formol saline
fixation time of formol saline in 35C /95C
24 hrs
fixation time of formol saline in 20-25*C
48 hrs
preserves enzymes and nucleoproteins
10% formol saline
demonstrates fats and mucins
10% formol saline
slow fixative and metachromic reactions of AMYLOID is reduced
10% formol saline
recommended for preservation and storage of surgical, post mortem and research specimen
10% neutral buffered formalin or phosphate buffered formalin
fixation time of 10% neutral buffered formalin or phosphate-buffered formalin
4-24 hrs
prevents precipitation of acid formalin pigments
10% neutral buffered formalin
best fixatives for tissues containing IRON PIGMENTS and elastic fibers
10% neutral buffered formalin
longer to prepare, positivity of mucin to PAS is reduced
10% neutral buffered formalin
reactivity of myelin to weigert’s iron hematoxylin is reduced
10% neutral buffered formalin
recommended for ROUTINE post mortem tissues
formol -corrosive or formol sublimate
disadvanatage is it forms mercuric chloride deposits and does not allow frozen tissue to be made
formol corrosive-formol sublimate
fixation time of formol corrosive-formol sublimate
3-24 hrs
excellent in staining procedure including SILVER RETICULUM METHODS
formol sublimate - formol corrosive
FIXATION IS FASTER
for rapid diagnosis, it fixes and dehydrates at the same time
alcoholic formalin/gendre’s fixative
good for preservation of glycogen and for MICROINCENERATION technique
alcoholic formalin/gendre’s tehnique
used to fix SPUTUM since it coagulates mucus
alcoholic fomalin or gendre’s fixative
produces gross hardening of tissues and causes PARTIAL LYSIS OF RBC
alcoholic formalin/gendre’s fixative
preservation of iron-containing pigments is poor
alcoholic formalin/gendre’s fixative
made up of 2 formaldehyde residues, linked by 3 carbon chains
glutaraldehyde
for routine light microscopic work
glutaraldehyde
fixation time of glutaraldehyde
1/2 to 2 hrs
● More expensive
● Less stable
● Penetrates tissues slowly
● Tends to make
tissue more brittle
● Reduces PAS positivity of
reactive mucin
glutaraldehyde
most common metallic fixative
mercuric chloride used in 5-7%
tissues may form black precipitates of mercury
mercuric chloride
trichrome staining is excellent and permits brilliant metachromatic staining of cells
mercuric chloride
recommended for renal tissues, fibrin, connective tissues and muscle
mercuric chloride
Rapidlyhardens the
outer layer of the
tissue with
incomplete fixation of
the center
mercuric chloride
causes considerable lysis of red blood cells and removes much iron from hemosiderin
mercuric chloride
INERTS TO FATS AND LIPIDS
mercuric chloride
mercuric chloride stock solution + glacial acetic acid
zenker’s fluid
a good general fixative for adequate preservation of all kinds of tissues and gives excellent staining results
zenker’s fluid
recommended for fixing small pieces of LIVER, SPLEEN, CONNECTIVE TISSUE FIBERS, AND NUCLEI
zenker’s fluid
fixation time of zenker’s fluid
12-24 hrs
recommended for trichome staining
zenker’s fluid
may act as mordant
zenlker’s fluid
excellent microanatomical fixative for PITUITARY GLAND, BONE MARROW, AND BLOO DOCNTAINING ORGANS such as SPLEEN AND LIVER
zenler-formol or helly’s solution
disadvantage is brown pigments are produced if tissues, especially blood containing organs, are allowed to stay in the fixative for more than 24 hrs due to rbc lysis
zenker-formol or helly’s solution
recommended mainly for TUMOR BIOPSIES especially of the skin
heidenhain’s susa solution
excellent cytologic fixative
heidenhain’s susa solution
weigert’s method of staining elastic fibers is not possible in ___ tissues
susa-fixed tissues
commonly used for BONE MARROW BIOPSIES
B-5 fixative
precipitate all proteins and adequately preserves CARBOHYDRATES
chromic acid
a strong oxidizing agent and is not used because it is hazardous
chromic acid
potassium dichromate is used in what aqueous solution
3%
it preserves LIPIDS AND MITOCHONDRIA
potassium dichromate
recommended for demonstration of CHROMATIN, MITOCHONDRIA, MITOTIC FIGUES, GOLGI BODIES, RBC, AND COLLOID CONTAINING TISSUES
regaud’s fluid or muller’s fluid
must always be freshly prepared
regaud’s or muller’s fluid
recommended for study of early DEGENERATIVE PROCESSES AND TISSUE NECROSIS
orth’s fluid
demonstrate ricketssia and other bacteria
orth’s fluid
preserves MYELIN better than buffered formalin
orth’s f;uid
for ACID MUCOPOLYSACCHARIDES
lead fixatives
fixes connective tissue mucin
tales up CARBON DIOXIDE to form INSOLUBLE CARBONATE especially on prolonged standing
lead fixatives
normally used in strong saturated aqueous solution
picric acid
HIGHLY EXPLOSIVE when dry
picric acid
recommended for fixation of EMBRYOS and PITUITARY biopsies
bouin’s solution
does not need washing out
bouin’s solution
this must never be washed in water before dehydration
picric acid
reduces/abolished FEULGEN reaction due to hydrolysis of nucleoproteins
bouin’s solution
better and less messy than bouin’s q
brasil’s alcoholic picroformol fixative
glacial acetic acid solidified at
17*C
contraindicated for cytoplasmic fixation since it destroys mitochondria and golgi bodies of cells
glacial acetic acid
these rapidly denatures and precipitates proteins by destroying hydrogen and other bond
alcohol fixatives
excellent for fixing and preserving glycogen, pigments, blood, tissue films, and smears
absolute alcohol
the color of the specimen can be preserved for photographic works using 80% alcohol
absolute alcohol
LOWER concentrations will cause rbc hemolysis and inadequately preserve leukocytes
absolute alcohol
excellent for fixing DRY AND WET SMEARS, blood and bone marrow smears
methyl alcohol
fixes and dehydrate at the same time aside from alcoholic formalin
methyl alcohol
used for fixing touch preparations
95% isopropyl alcohol
preserves but does not fix glycogen
ethyl alcohol
preserves nucleoproteins and nucleic acid, hence used for histochemistry and enzyme studies
ethyl alcohol
Recommended for fixing chromosomes, lymph glands and urgent biopsie
carnoy’s fluid
considered as the MOST rapid fixative
carnoy’s fluid
fixes and dehydrate aside from alcholic formalin, methyl alcohol
carnoy’s fluid
used to fix brain tissues for the diagnosis of rabies
carnoy’s fluid
fixes materials for ultrathin sectioning in elcron microscope
osmium tetroxide
uses tap water for washing out
hellys
zenkers
flemming
formalin
osmic acid
uses 50-70% of alcohol for washing out
picric acid
uses alcoholic iodine for washing out
mercuric fixative
fixative for proteins
nbc, paraformalehyde
fixative for enxymes
frozen sections
fixative for lipids F
frozen section, glut, osmium tetroxide
nucleic acid fixative
alcholic fixatives
mucopolysaccahrides
frozens sections
biogenic amines
bouins, NBF
glycogen
alcohoilic fixatives