Fixation, Safety, Fresh Tissue Flashcards
satisfactory for routine paraffin sections
aldehyde fixative
stains CNS and postmortem tissues
10% formol saline
recommended for preservation and storage of ** surgical*, post-mortem, and research specimens
10% NBF or phosphate buffered formalin
recommended for routine post-mortem tissues
formal-corrosive
good for preservation of glycogen and micro-incineration technique; and used to fix sputum since it coagulates mucus
alcoholic formalin (Gendre’s) fixative
buffered state of this fixative followed by secondary fixation in osmium tetroxide is satisfactory for electron microscopy
2.5% solution is used for small fragments and needle biopsies fixed in 2-4 hours at room temperature
4% solution for larger tissues fixed in 6-8 hours up to 24 hours
glutaraldehyde
routine fixative of choice for preservation of cell detail in tissue photography
most common metallic fixative
mercuric chloride
recommended for fixing small pieces of liver, spleen, connective tissue fibers and nuclei
zenker’s fluid
excellent microanatomic fixative for pituitary gland, bone marrow, and blood containing organs such as spleen and liver
zenker-formol (Helly’s solution)
main fixative for tumor biopsies especially skin; excellent cytologic fixative
heidenhain’s susa
used for bone marrow biopsies
Lillie’s B5 fixative
precipitates all proteins and adequately preserves carbohydrates
chromic acid
preserves lipids and mitochondria
potassium dichromate
recommended for demonstration of chromatin, mitochondria, mitotic figures, golgi bodies, BC, and colloid containing tissues
Regaud’s (Muller) fluid
recommended for early degenerative process and tissue necrosis. demonstrates Rickettsia (rocky mountain fever) and other bacteria
Orth’s fluid
recommended for acid mucopolysaccharides and fixes connective tissue mucin
lead fixatives
recommended for fixation of embryos and pituitary biopsies
Bouin’s solution
normally used in conjuction with other fixatives to form a compound soltuion
glacial acetic acid
denatures and precipitates proteins by destroying hydrogen and other bonds
may be used both as fixative and dehydrating agent
alcoholic fixatives
excellent for fixing dry and wet smears, blood smears, and bone marrow tissues
methyl alcohol 100%
used for fixing touch preparations
isopropyl alcohol 95%
recommended for fixing chromosomes, lymph glands, and urgent biopsies
most rapid fixative
Carnoy’s fluid
recommended for fixing mucopolysacchrides and nuclear proteins
Newcomer’s fluid
usuall for frozen tissue section and preparation of bacteriologic smears
heat fixation
recommended for study of water diffusible enzymes especially phospatases and lipases
used in fixing brain tissues for diagnosis of rabies
acetone
recommended for cytoplasmic structures
Flemming’s solution without acetic acid
most common chrome-osmium acetic acid fixative which is excellent nuclear fixative and permanently fixes fats
Flemming’s solution
fixation with this solution causes complete denaturation of proteins
osmium tetroxide (osmic acid)
what fixative is explosive when dried out
picric acid
are chemicals that cause reversible inflammatory effects at the site of contact with living tissue, especially the skin, eyes and respiratory passages
irritants
cause destruction or irreversible alterations when exposed to living tissue, or destroy certain inanimate surfaces (generally a metal)
corrosive chemicals
cause allergic reactions in some exposed workers, not just in hypersensitive individuals. Sensitization may occur at work because of the high exposure level
sensitizers
substances that induce tumors
carcinogens
causes death by ingestion, skin contact, or inhalation
toxic materials
is the simplest, least invasive test and uses the smallest needle to simply remove cells from the area of abnormality. This is not always adequate to obtain a diagnosis, depending on the area to be biopsied
fine needle aspiration
removes not only cells, but also a small amount of the surrounding tissue. This provides additional information to assist in the examination of the lesion
core needle biopsy
takes out even more surrounding tissue. It takes out some of the abnormality, but not all. The doctor will slice into the lesion and remove only a portion of it. If the lesion is found to be cancerous, further surgery may be needed to remove or excise the entire lesion.
incisional biopsy
generally removes the entire area in question
excisional biopsy
is considered the primary technique for obtaining diagnostic full-thickness skin specimens, yielding a 3- to 4- mm cylindrical core of tissue sample
punch biopsy
where small fragments of tissue are “shaved” from a surface
shave biopsy
where tissue is scooped or spooned to remove tissue or growth from body cavity such as endometrium and cervical canal
curettings
fixative for human skin
alcoholic formaldehyde
excellent fixative for soft and delicate structures
bouin’s solution
excellent fixative for glycogen
Brasil’s alcoholic picroformol fixative
used to fix brain tissue for diagnosis of rabies and an excellent fixative for glycogen
carnoy’s fluid
used extensively for neurological tissues which fixes myelin and peripheral nerves
fixative
osmium tetroxide (osmic acid)
