Fixatives Flashcards
What is the pH range when a formalin pigment may form?
below 6
What are the Clarke components?
absolute alcohol and acetic acid
What are the Gendre components?
Alcohol saturated with Picric acid, formaldehyde, acetic acid
What are the B-5 components?
Mercuric chloride, formaldehyde, sodium acetate
What are the Bouin’s components?
Picric acid, formaldehyde, acetic acid
What are the Carnoy components?
Chloroform, absolute alcohol, acetic acid
What are the Helly Components?
Mercuric chloride, potassium dichromate, formaldehyde
What are the Hollande components?
Picric acid, formaldehyde, acetic acid, copper acetate
What are the Orth components?
Potassium dichromate, formaldehyde, sodium sulfate.
What are the Zamboni components?
Picric acid, paraformaldehyde, phosphate buffer
What are the Zenker components?
Mercuric chloride, potassium dichromate, acetic acid
What are the fixtives for Urates?
Carnoy or ethanol
How to remove Mercury Pigment?
Iodine, then sodium thiosulfate
How to remove chrome pigment?
Wash tissue in running water before dehydration
How to remove formalin pigment?
absolute alcohol with picrid acid or 70% alcohol containing ammonium hydroxide (aka alkaline alcohol)
What is another name for formalin pigment?
Black acid hematin
What are uses of Clarke Solution?
Blood smears and frozen sections
What is the fixative also used as a mordant in Trichrome stain?
Picric acid
What are uses of Methanol as a fixative?
Touch preps and blood smears
What fixative is not good for PAS?
gluteraldehyde
What fixative is used for pheochromocytomas?
Orth solution
What is a secondary fixative used for EM?
Osmium tetroxide
What fixatives are not good for silver stains?
Helly, B-5, Zenker
What are the non-additive fixatives?
Methanol, ethanol, acetone
What is the advantage of Zinc Formalin over Formalin?
Superior nuclear detail
What are the actions of acetic acid?
Coag nucleoprotiens, cell swelling, red cell destruction
What chemical is used to remove excess picric acid after fixation in Bouin’s?
50-70% alcohol
What fixative is best for fats?
osmium tetroxide
What fixatives are used to fix blood smears?
Clarke or methanol
what are the non-aqueous fixatives?
acetone, ethanol, methanol, clarke, carnoy
Bouin solution is prepared by combining picric acid with what?
formaldehyde and glacial acetic acid
Fixatives containing chromate salts usually require:
washing in water
Which of the following fixatives should be used when making a diagnosis of gout?
absolute alcohol
Aldehyde fixatives are used for electron microscopy preparations because they:
preserve cell ultrastructure
Which would be a good fixative for a silver stain?
glutaraldehyde
