Histology Techniques & Technology Flashcards

According to OSHA's Hazard Communication Standard, what document provides detailed safety information about a specific chemical, including handling, storage, and first-aid measures?

Answer: Safety Data Sheet (SDS)

The Safety Data Sheet (SDS), previously called MSDS, is the standardized document required by OSHA's HazCom Standard to communicate chemical hazards and safe handling procedures.

Xylene substitutes (xylene alternatives) are increasingly used in tissue processing primarily to reduce exposure to which hazard?

Answer: Volatile organic compounds (VOCs) with hepatotoxic and neurotoxic potential

Xylene is a volatile organic compound with recognized hepatotoxic and neurotoxic properties; xylene substitutes reduce worker exposure while maintaining clearing efficacy.

What is the purpose of a proficiency testing (PT) program for a histology laboratory?

Answer: To externally verify laboratory performance and ensure accurate results

Proficiency testing programs send unknown specimens to the laboratory for testing; results are compared to peer laboratories to verify that the lab's methods are accurate and reproducible.

In histology, what is the term for the gradual fading of a stained section over time when exposed to light?

Answer: Photobleaching (fading)

Photobleaching or fading occurs when light energy breaks the chromophore bonds in dye molecules, causing loss of color intensity in stained sections.

Which of the following describes the correct sequence for deparaffinization before routine H&E staining?

Answer: Xylene → graded alcohols → water

Deparaffinization begins with xylene to dissolve paraffin, then graded alcohols to remove xylene, and finally water to hydrate the tissue for aqueous staining.

Automated tissue processors in the histology lab are most commonly operated using which processing mode to prevent overnight tissue damage?

Answer: Timed or continuous carousel with vacuum/pressure cycles

Modern automated processors use timed cycles with vacuum and/or pressure to accelerate reagent penetration and can be programmed to complete processing just before the next workday begins.

A technician notices that sections consistently show a thick, uneven ribbon during paraffin sectioning in winter. The MOST likely cause is:

Answer: The paraffin block is too cold, causing compression

Cold paraffin blocks compress during sectioning rather than cutting cleanly; warming the block face slightly with a warm hand or lamp helps produce even ribbons.