Fixatives OSMIC ACID FIxatives

Question 1

● Pale yellow powder in water (6% in 20C)
● Ultrathin sections in Electron Microscopy
● E: Fixes and stains conjugated fats and lipids black
● DADV: very expensive, very volatile, inhibits hematoxylin
● Tissue-to-fixative ratio: 1:5

Answer 1

OSMIC ACID FIXATIVES

Question 2

● Nuclear fixative (24-48 hrs)
→ It can fix the nucleus
● Most common osmic acid fixative
● Effect: permanently fixes fat
● ADV: need less amount of fixative

Answer 2

FLEMMING’S SOL’N W/ GAC (GLACIAL ACETIC
ACID)

Question 3

Cytoplasmic fixative (24-48 hrs)

Answer 3

FLEMMING’S SOL’N W/O GAC (GLACIAL ACETIC
ACID)

Question 4

● Incorporated into compound fibers
● Weak decalcifying agent, thus has softening effect on dense fibrous tissues

Answer 4

TRICHLOROACETIC ACID

Question 5

● Use at ice cold temperature (-5 to 4 degree celsius)
● DADV: Dissolve fat, evaporates rapidly

Answer 5

ACETONE

Question 6

● Another method wherein we can add heat fixation or apply it on our fixative with our tissue cassettes in order to increase the process of fixation
● Involves thermal coagulation of tissue proteins for rapid
diagnosis

Answer 6

HEAT FIXATION