Dehydration

Question 1

Dehydration

Answer 1

the procedure whereby calcium and lime salts are removed from tissues

Question 2

When does dehydration done

Answer 2

After fixation adn before impregnation

Question 3

Bones and decalcified tissues are cut with

Answer 3

fine fret-saw and trimmed with a hand razor

Question 4

Appear as dark purple granular masses with lighter purple halos after hematoxylin staining

Answer 4

Microcalcification

Question 5

The resistance when a tissue surface with small foci of calcification is sectioned with a microtome knife

Answer 5

Grating sensation

Question 6

Remedy for grating sensation

Answer 6

Place the block face down on a cotton pad or gauze saturated with 10% HCl for approximately an hour

Question 7

Calcium may be removed by

Answer 7

Acids, chelating agents, Ion exchange resins, and electrical ionization

Question 8

Factors influencing the rate of decalcification

Answer 8

concentration, volume of decalcifying agent, temperature, mechanical agitation, sonificaton

Question 9

Optimum temperature

Answer 9

18-30 degree Celsius

Question 10

Impaired nuclear staining of Van Geison’s stain for collagen fibers

Answer 10

37 degree Celsius

Question 11

Tissue will undergo complete digestion within 24-48 hours

Answer 11

55 degree Celsius

Question 12

Most widely used agents for routine decalcification of large amounts of bony tissues. Stable, easily available, relatively inexpensive

Answer 12

Acid decalcifying agents

Question 13

Most common and fastest decalcifying agent. Recommended for routine purposes

Answer 13

Nitric acid

Question 14

Recommended concentration for nitric acid

Answer 14

5-10%

Question 15

Recommended for urgent biopsy, and for needle and small biopsy

Answer 15

10% Aqueous Nitric Acid Solution

Question 16

Recommended for urgent biopsies and less tissue distruction than 10% aqueous nitric acid

Answer 16

Formol Nitric Acid

Question 17

Recommended for routine purposes

Answer 17

Perenyi’s Fluid

Question 18

Most rapid decalcifying agent

Answer 18

Perenyi’s Fluid

Question 19

It is inferior to nitric acid. Slower action greater distortion

Answer 19

Hydrochloric acid

Question 20

may be recommended for surface decalcification of the tissue block

Answer 20

1% HCl solution with 70% alcohol

Question 21

Usually contain HCl

Answer 21

Rapid proprietary solution

Question 22

Usually contain buffered formic acid or formalin/ formic acid

Answer 22

Slow proprietary solution

Question 23

moderately rapid decalcifying agent. It is recommended for teeth and small pieces of bone

Answer 23

Von Ebner’s Fluid

Question 24

Moderate-acting decalcifying agent (addition of citrate accelerates decalcification)

Answer 24

Formic acid

Question 25

Recommended for routine decalcification of postmortem research tissue and for small pieces of bones and teeth

Answer 25

Formic acid

Question 26

It is the only weak acid used extensively as a primary decalcifying agent

Answer 26

Formic acid

Question 27

Recommended for autopsy materials, bone marrow, cartilage, and tissue studied for research purposes

Answer 27

Formic Acid-Sodium Citrate Solution

Question 28

Suitable only for small spicules of bone

Answer 28

Trichloroacetic acid

Question 29

Suitable only for minute pieces of bone

Answer 29

Sulfurous acid

Question 30

Decalcifies minute bone spicules both a fixative and decalcifying agent

Answer 30

Chromic acid (Flemming's fluid)

Question 31

Permits excellent nuclear acid cytoplasm staining

Answer 31

Citric acid-citrate buffer solution (pH 4.5)`

Question 32

Substance which combine with calcium ions and other salts to form weakly dissociated complexes and facilitate removal of calcium salt

Answer 32

Chelating agents

Question 33

Most common chelating agent

Answer 33

EDTA (Versene)

Question 34

traditionally referred as Acid. Also used as anticoagulant and water softener.

Answer 34

EDTA (Versene)

Question 35

A slow decalcifyng agent and also an excellent bone decalcifier for immunohistochemical or enzyme staining

Answer 35

EDTA

Question 36

Ammonium form of polystrene resin

Answer 36

Ion exchange resin

Question 37

Hastens decalcification by removing calcium ions from formic acid containing decalcifying solutions and not recommended for fluids containing mineral acids

Answer 37

Ion exchange resin

Question 38

Ratio of Ion exchange resin

Answer 38

20-30 times the volume of the tissue

Question 39

degree of decalcification measured by

Answer 39

physical or x-ray method

Question 40

Is the process whereby positively charged calcium ions are attached to a negative electrode and subsequently removed from the decalcifying solution

Answer 40

Electrophoresis (Electrical ionization)

Question 41

The priniciple is similar to that of chelating agents but utilizez electricity and is dependent upon a supply of direct current to remove calcium deposits

Answer 41

Electrophoresis

Question 42

done by touching or bending the tissue with the fingers to determine consistency of tissues or pricking tissue with a fine needle or a probe

Answer 42

Physical or Mechanical test

Question 43

very expensive and most ideal, most sensitive and most reliable method of determining extent of decalcification. Not recommended for mercuric chloride-fixed tissues

Answer 43

X-ray or radiological method

Question 44

simple, reliable, and convenient method. Recommended for routine purposes by precipitation of insoluble calcium hydroxide or calcium oxalate

Answer 44

Chemical method (Calcium oxalate method)

Question 45

The decalcifying agent is usually changed for

Answer 45

24-48 hours

Question 46

Indicates that there is still calcium in the solution

Answer 46

Presence of cloudiness

Question 47

Complete decalcification

Answer 47

Solution remains clear after 30 minutes