HT Quality Control & Assurance 4

Question 1

A newly prepared Alcian Blue pH 2.5 solution fails to stain acid mucins in the positive control. After checking pH, what is the next most likely variable to investigate?

Accepted Answer

Acetic acid concentration used to adjust pH

Answer

Alcian Blue pH 2.5 requires precise pH adjustment using acetic acid; incorrect concentration alters ionization of the dye and prevents mucin binding.

Question 2

What is the purpose of including an 'external' control section mounted on the same slide as the patient tissue in IHC?

Accepted Answer

To confirm that all reagents and steps performed identically for the patient and control tissue

Answer

Mounting control and patient tissue on the same slide ensures they undergo identical processing, validating that any result difference is due to biology, not technique.

Question 3

During tissue processor QC, a technician finds all paraffin-embedded tissues are soft and incomplete. Which processor station failure is most likely?

Accepted Answer

Incomplete dehydration in alcohol stations

Answer

Incomplete dehydration leaves residual water in tissue, which prevents paraffin infiltration and results in soft, incompletely embedded blocks.

Question 4

Which element of a QC program specifically monitors whether patient results fall within medically appropriate ranges compared to prior specimens?

Accepted Answer

Delta check

Answer

A delta check compares a patient's current result to a previous result to detect unexpected changes that may indicate specimen or clerical errors.

Question 5

A Grocott's Methenamine Silver (GMS) stain shows pale gray fungi instead of sharp black outlines. What is the most likely problem?

Accepted Answer

Silver solution under-reduced or developer time too short

Answer

GMS relies on reducing silver ions to metallic silver on fungal cell walls; insufficient reduction time produces pale gray instead of crisp black.

(HT) Histotechnician Certification Practice Test

(HT) Histotechnician Certification Practice Test

HT Quality Control & Assurance 4