Errors During Tissue Processing

Question 1

How to test unknown strengths of alcohol?

Answer 1

Float an alcoholmeter in the solution

Question 2

How to remedy improperly fixed tissue blocks?

Answer 2

deparaffinized

remove paraffin

Question 3

How to soften tissues?

Answer 3

soak in detergent + water

Question 4

Broken slides

Answer 4

soak with xylene and remove coverslip → remount

Question 5

opaque tissue

Answer 5

reclear

Question 6

airholes

Answer 6

re-impregnate

Question 7

torn and crumbly sections

Answer 7

remove paraffin → redehydrate → clear → embed

Question 8

deformalinize tissue section

Answer 8

refix formalin with other fixative → deparaffinize in ammonia water

Question 9

reclaming tissue on wrong solution

Answer 9

place in cold tap water

Question 10

cutting blood-containing tissues

Answer 10

• soak in tap water
• soak in glycerin + 60% alcohol

Question 11

collodionization

keeping section from float-off

Answer 11

deparaffinize with xylene and absolute alcohol

Question 12

shrinkage

Answer 12

repeat whole procedure

Question 13

crystalline wax

Answer 13

re-embed

Question 14

unequal thickness

Answer 14

reduce knife tilt

Question 15

improperly dehydrated tissue blocks

Answer 15

remove paraffin → rehydrate → re-embed

Question 16

retaining slides

Answer 16

place in xylene

Question 17

removing folds of pleated paraffin sections

Answer 17

use 50% alcohol

Question 18

compressed, wrinkled, or jammed sections

Answer 18

re-sharpen the knife

Question 19

moist and crumbly paraffin block

Answer 19

re-impregnate → re-embed

Question 20

horizontal/parallel lines or furrows across section

Answer 20

treat with phenol or collodionize → reduce knife tilt