HT Frozen Sections & Cryostat Techniques 3

Question 1

What is the standard method for transferring a frozen section from the cryostat stage to a glass slide?

Accepted Answer

Placing a room-temperature slide directly onto the section so it thaws and adheres

Answer

Floating the section on a warm water bath and lifting

Answer

Picking up the section carefully with fine forceps

Answer

Using a fine camel-hair brush to sweep the section onto the slide

Question 2

What does the abbreviation 'OCT' stand for in the context of cryostat embedding media?

Accepted Answer

Optimal Cutting Temperature

Answer

Organic Compound for Tissue

Answer

Osmium Cryo-embedding Technique

Answer

Ovoid Cell Tissue medium

Question 3

For intraoperative consultation, what is the accepted turnaround time from specimen receipt to frozen section diagnosis?

Accepted Answer

15–20 minutes

Answer

2–5 minutes

Answer

30–45 minutes

Answer

60–90 minutes

Question 4

Which fixative would cause LOSS of lipids from tissue intended for frozen section lipid staining and should therefore be avoided?

Accepted Answer

Absolute ethanol

Answer

Calcium formalin

Answer

10% neutral buffered formalin

Answer

Glutaraldehyde

Question 5

What is a common cause of thick, uneven, or 'chattering' frozen sections in the cryostat?

Accepted Answer

A dull or nicked cryostat knife

Answer

Tissue temperature that is excessively cold

Answer

Using too much OCT compound on the chuck

Answer

Tissue block that is too large

Question 6

What is the recommended rapid freezing method to minimize ice crystal artifact when preparing fresh tissue for enzyme histochemistry frozen sections?

Accepted Answer

Rapid quenching in isopentane cooled by liquid nitrogen, or CO2 cryospray

Answer

Immersion directly in liquid nitrogen

Answer

Placement in a standard -20°C freezer

Answer

Dry ice and acetone slurry immersion

Question 7

What is the purpose of 'quenching' tissue in liquid nitrogen vapor before cryostat sectioning for enzyme histochemistry?

Accepted Answer

To achieve rapid freezing that preserves labile enzyme activity

Answer

To sterilize the tissue and prevent contamination

Answer

To chemically fix proteins before sectioning

Answer

To remove excess extracellular fluid from the tissue