FIXATIVES PICRIC ACID

Question 1

● Normally used in strong aqueous solution (1%)
● Glycogen demonstration
● Highly explosive when dry
→ Remedy: add distilled H2O or 0.5-1% saturated alcohol
● Yellowing effect
→ Remedy: immerse in Li2CO3 with 70% ROH -> water->70% ethanol -> 5% Na thiosulfate -> water

Answer 1

PICRIC ACID FIXATIVES

Question 2

● For embryo and pituitary biopsies and tissues to be stained with Masson’s Trichrome
● ADV: minimum ce shrinkage and tissue hardening due to counterbalance effect of galactic HAc (swelling) and picric acid
(shrinking)
● DADV: poorly penetrates large tissue, thus limited to small fragments of tissues

Answer 2

BOUIN’S

Question 3

Better and less messy than Bouin’s

Answer 3

BRASIL’S ALCOHOLIC ICROFORMOL

Question 4

● Incorporated in compound fixatives
● Solidifies at 17 degrees celsius
● Important for nuclear fixatives (precipitates nucleoproteins, chromatins)
● Destroys mitochondria and Golgi elements, thus not for cytoplasmic fixation

Answer 4

GLACIAL ACETIC ACID FIXATIVES