histopath

Question 1

Brittle or hard tissue

Answer 1

Prolonged fixation
Prolonged dehydration
Prolonged clearing
Prolonged paraffin infiltration in overheated
paraffin oven
Drying out of tissue before actual fixation
Failure to give special handling of tissues when
treated with routine processing methods REMEDY: Tissues may be softened by soaking in a small dish or bowl
containing water with detergent, phenol or Molliflex.

Question 2

Clearing agent turns milky as
soon as tissue is placed in it

Answer 2

Water not completely removed due to incomplete
dehydration
REMEDY: Repeat dehydration with absolute alcohol, then clear again

Question 3

On trimming, tissue smells of
clearing agent

Answer 3

Clearing agent not completely removed due to
insufficient impregnation
REMEDY: Block is trimmed down nearest to the tissue, remaining wax
is melted on embedding oven and paraffin impregnation is
repeated, changing the paraffin at least once before blocking.

Question 4

Tissue is opaque, section–cutting
is difficult due to presence of
alcohol

Answer 4

Insufficient clearing
REMEDY: Repeat clearing; if object has already been embedded,
prolong clearing up to 12 hours then re–embed

Question 5

Tissue shrinks away from wax
when trimmed

Answer 5

Insufficient dehydration, therefore incomplete
clearing and impregnation
REMEDY: Repeat the whole procedure

Question 6

Tissue is soft when block is
trimmed

Answer 6

Incomplete fixation
REMEDY: Repeat fixation

Question 7

Airholes found on tissue during
trimming

Answer 7

Incomplete impregnation
REMEDY: Repeat impregnation

Question 8

On trimming, wax appears
crystalline

Answer 8

Contaminated wax
REMEDY: Re–embed in freshly filtered wax

Question 9

Paraffin block after cooling is
moist and crumbles

Answer 9

Insufficient paraffin impregnation
REMEDY: Repeat paraffin impregnation then
re–embed