Frozen Sections & Cryostat Techniques Flashcards

What is the primary purpose of a cryostat in histology?

Answer: To section frozen tissue at controlled low temperatures

A cryostat is a refrigerated microtome that sections frozen tissue at controlled low temperatures, preserving labile enzymes and lipids that would be destroyed by standard processing.

What temperature range is typically maintained inside a cryostat cabinet for routine soft tissue sectioning?

Answer: -15°C to -25°C

Cryostat cabinets are typically maintained between -15°C and -25°C, which is optimal for sectioning most soft tissues without causing them to shatter.

Which embedding medium is most commonly used to support tissue for frozen sections in a cryostat?

Answer: Optimal Cutting Temperature (OCT) compound

OCT (Optimal Cutting Temperature) compound is the standard embedding medium for cryostat sectioning because it supports the tissue block without interfering with most staining procedures.

What is the primary advantage of frozen sections over routine paraffin-embedded sections?

Answer: Rapid preparation time enabling intraoperative diagnosis

The primary advantage of frozen sections is rapid turnaround (15–20 minutes), allowing surgeons to receive an intraoperative diagnosis without significantly prolonging the procedure.

Which type of tissue component is BEST demonstrated using frozen sections rather than paraffin-embedded sections?

Answer: Lipids and neutral fats

Lipids are dissolved by the organic solvents used during paraffin processing, so frozen sections must be used to demonstrate lipid droplets and neutral fats in tissue.

Which staining method is most commonly used for rapid staining of intraoperative frozen sections?

Answer: Hematoxylin and eosin (H&E)

H&E is the most common rapid stain for frozen sections because it provides adequate nuclear and cytoplasmic detail for diagnostic purposes within a few minutes.

What is the typical section thickness range for routine diagnostic frozen sections?

Answer: 8–12 micrometers

Frozen sections are typically cut at 8–12 micrometers because frozen tissue cannot be sectioned as thinly as paraffin-embedded tissue and requires greater thickness for intact sections.