DECAL Flashcards
aka demineralization
DECALCIFICATION
calcium or lime salts are removed from tissues
following fixation
DECALCIFICATION
Wash the decalcified
specimen for
24-48 hrs
Quantity of decal solution:
> 20 vol. of specimen
most common and fastest decal agent
5%-10% Nitric Acid
Rapid acting, good nuclear staining decal agent
Formol-Nitric Acid
Lessen yellow tissue discoloration by 5% sodium sulfate or 0.1% urea
Formol-Nitric Acid
Decalcifying and tissue softener but slow acting
Perenyi’s
silver impregnation of nerve fibers
De Castro’s Fluid
slower, greater tissue distortion decal agent
Hydrochloric Acid (HCl)
Most rapid, poor nuclear staining
Phloroglucin-Nitric Acid
Must be removed by 3 changes of 70-90% ethanol
Phloroglucin-Nitric Acid
duration for small specimens
1 to 3 weeks
calcium ions are attracted to a
negative electrode (cathode)
Simple, reliable and recommended for routine
purposes (test)
Chemical Test
best general decalcifying agent and fixative
5% Formic acid
Buffer solution for electrophoresis
8% HCL + 10% Formic acid
Excellent nuclear and cytoplasmic staining
5% Formic acid
Very weak, for minute bone pieces
Sulfurous Acid
Slow; not recommended for urgent examinations.
Trichloroacetic Acid (TCA)
duration for dense cortical bone
6 to 8 weeks:
Highly corrosive, carcinogenic and an environmental hazard
Chromic Acid (Flemming S)
Removal of calcium and exchanged with ammonium ions from ammonium-sulfonated polystyrene
ION EXCHANGE RESIN
aka muriatic acid
Hydrochloric Acid (HCl)
ph level that allows binding and does not destroy tissue components
pH 7.0 to 7.4 (neutral):
Fixative and decalcifier
Chromic Acid (Flemming S)
If there are small amounts =
ppt will show after 10 Mins
uses ammonium-sulfonated polystyrene +
formic acid
Resins
Dissolution of calcium by an acid
ION EXCHANGE RESIN
safe choice for decalcification
*formic acid
may cause swelling or make tissues
soapy
molliflex
Calcified specimen which are 2-3mm thick could be decalcified within
2 to 3hrs
for urgent diagnosis
for urgent diagnosis
Ideal and reliable, expensive, not applicable on
mercuric chloride fixed tissues (test)
Radiologic test
Washing Out: to remove acids in Small specimen
30 mins
neutralization agent for post decal
2% LiCo
5 to 10% NaHCO3
If large amount of calcium is present
= immediate
precipitation
Washing Out: to remove acids
large specimen
1-4hrs
Complete decalcification
Clear fluid