GROUP QUESTIONS AND ANSWERS
WITH SOLUTIONS 2024
What fixatives are preferred for staining Nuclei?
Carnoy
Zenkers
10% NBF
Acetic Acid
Bouins
Alcoholic Formalin - ANSWER Carnoy and Acetic Acid
After formalin fixation, nuclei often show coalescence of the __________ into strands with intervening
clear spaces. - ANSWER Chromatin
What are the 2 chemicals that fix lipids? - ANSWER Chromic Acid and Osmium Tetroxide
What temperature does formaldehyde start to react with RNA? - ANSWER 45C
What temperature does formaldehyde start to react with DNA? - ANSWER 65C
Why doesn't glycogen get washed away in processing? - ANSWER Glycogen would get washed away in
processing if it weren't for the fixed proteins trapping it in the tissue
If immunoflourescence is desired, what fixative must be used?
10% NBF
Bouins
Zamboni
, Frozen, not fixed
Zenker - ANSWER Frozen; Not fixed
Define Osmolality - ANSWER Defined as the number of particles in a solution vs the tissue
What happens to the fixative if the volume of the tissue is greater than the volume of the fixative? -
ANSWER If the volume of the tissue is greater than the fixative, the fixative composition can be altered
due to too much of the fixative combining with tissue proteins and altering the chemical makeup of the
fixative
At what temperature can negatively affect tissue morphology? - ANSWER 45C
What is the approximate pH of tissue fluids? - ANSWER 7.2-7.4
What type of fixative must be used for a disease with urate crystals?
Alcohols
Zamboni
Frozen, not fixed
10% NBF
Zenker - ANSWER Alcohols
What is the pH that Electron Microscopy be done at? - ANSWER 7.2-7.4
What pH may alter the tissue significantly?
4
5
6
7