ASCP Hematoxylin and Eosin Staining 2

Question 1

What does 'over-differentiation' of hematoxylin produce in an H&E section?

Accepted Answer

Pale or unstained nuclei

Answer

Over-differentiation removes too much hematoxylin, resulting in pale or ghost nuclei that are difficult to visualize.

Question 2

What type of hematoxylin is most commonly used in routine histology laboratories in the US?

Accepted Answer

Harris hematoxylin

Answer

Harris hematoxylin is the most widely used progressive/regressive hematoxylin in US histology labs for routine H&E staining.

Question 3

Which method of hematoxylin staining requires a differentiation step?

Accepted Answer

Regressive staining

Answer

Regressive staining over-stains tissue and then differentiates to remove excess dye from non-target sites, requiring a controlled acid-alcohol step.

Question 4

What is a common cause of eosin staining appearing too pale in H&E sections?

Accepted Answer

Insufficient eosin concentration or exhausted eosin solution

Answer

Diluted or exhausted eosin solution lacks sufficient dye concentration to adequately stain cytoplasmic proteins.

Question 5

Which reagent is used to mount coverslips on H&E sections stained using an alcohol-based final dehydration?

Accepted Answer

Xylene-based mounting medium (e.g., Permount)

Answer

Xylene-based mounting media like Permount are miscible with the dehydrated, xylene-cleared sections and provide permanent, clear mounts.

ASCP - Histotechnician Test Practice Test