Decalcification Flashcards
what is decalcification
to remove minerals from bone or other calcified tissue
effect of decalcification
hard cutting of tissuese
effect of over-calcification
will hardly react to eosin
calcium may be removed by one of the following agents, enumerate.
acids, chelating agents, ion exchange resins, electrical ionization
enumerate the acid decalcifying agents
- nitric acid
- hydrochloric acid
- formic acid
- formic acid - sodium citrate solution
- trichloroactetic acid
- sulfurous acid
- chromic acid
- citric acid
most common and fastest decalcifying agent
nitric acid
aqueous nitric acid solution 10% components and decal time
concentrated nitric acid + distilled water
12-24 hours
recommended for urgent biopsies, needle, and small biopsies
aqueous nitric acid solution 10%
FORMOL-NITRIC ACID (10%) components and decalcification time
concentrated nitric acid + strong formaldehyde + distilled water
1-3 days
component and decal time of perenyi’s fluid
10% nitric acid + 0.5% chromic acid + absolute ethyl alcohol
2-7 days
phloroglucin nitric acid components and decal time
concentrated nitric acid + phloroglucin + 10% nitric acid
12-24 hours
most rapid decalcifying agent
phloroglucin nitric acid
enumerate the 4 decalcifying agents under NITRIC ACID
formol-nitric acid, aqueous nitric acid solution 10%, perenyi’s fluid, phloroglucin nitric acid
inferior to nitric acid due to its lower action and greater distortion
hydrochloric acid
give an example of a hydrochloric acid decalcifying agent
von ebner’s fluid
von ebner’s fluid components
Saturated aqueous solution of 36% NaCl + conc. HCL _ distilled water
this acid decalcifying agent recommended for teeth and small pieces of bones
von ebner’s fluid
the only weak acid used extensively as primary decalcifying agent for decalcification of post-mortem tissues not for urgent exams
formic acid
component and decalcification time of formic acid
formic acid + 10% formol saline
2-7 days
components and decal time of formic acid - sodium citrate solution
20% aqueous sodium citrate + 45% formic acid
3-14 days
recommended for autopsy materials, bone marrow cartilage, and tissue studied for research
formic acid - sodium citrate solution
components and decal time of trichloroacetic acid
TCA + 10% formol saline
4-8 days
weak decalcifying solution suitable only for minute pieces of bone
sulfurous acid
chromic acid (flemming’s solution) components
chromic acid + osmium tetroxide + glacial acetic acid
citric acid - citrate buffer solution pH, component, and decal time
4.5
7% citric acid monohydrate aqueous solution + 7.4% ammonium citrate (anhydrous) aqueous solution + 1% zinc sulfate aqueous solution + few drops of chloroform
6 days
most common chelating agent
EDTA
substances which combine calcium ions and other salts
chelating agents
commercial name of edta
versene and sequestrene
ion exchange resin is an ammonium form of __
polystyrene resin
removes calcium ions from formic acid thereby increasing solubility from the tissue
ion exchange resin
ion exchange resin is not recommended for fluids containing mineral acids such as __
nitric or hydrochloric acid
process whereby positively charged calcium ions are attached to a negative electrode and subsequently remove from the decalcifying agent
electrophoresis
solutions used in electrophoresis
88% formic acid, concentrated HCl, distilled water
enumerate the 3 ways to measure the extent of decalcification
physical or mechanical method, xray/radiological, chemical/calcium oxalate test
most ideal, most sensitive, most reliable method which is not recommended for mercuric chloride-fixed itssues
xray/radiological
reliable, convenient method recommended for routine purposes and the decalcifying fluid is changed every 24-48 hrs
chemical method/calcium oxalate test
solutions used in calcium oxalate test
concentrated ammonium hydroxide, saturated aqueous ammonium oxalate
presence of cloudiness in chemical method indicates?
presence of Ca (incomplete decalcification)
