Medical Laboratory Technician Exam Blood Bank and Transfusion 3

Question 1

Which test detects weak subgroups of A (A3, Ax) that are missed by routine ABO typing?

Accepted Answer

Adsorption-elution technique

Answer

Adsorption-elution concentrates anti-A onto cells with very few A antigens, allowing confirmation of weak A subgroups not detected by direct agglutination.

Question 2

Cold agglutinin disease is most commonly caused by antibodies of which specificity?

Accepted Answer

Anti-I

Answer

Anti-I is the specificity of the monoclonal IgM cold agglutinin produced in cold agglutinin disease, reacting optimally at 0–4°C.

Question 3

Which preservative solution allows red blood cells to be stored for up to 42 days?

Accepted Answer

AS-1 (Adsol)

Answer

Additive solutions such as AS-1 (Adsol) extend RBC shelf life to 42 days by providing extra nutrients for RBC metabolism.

Question 4

A unit of FFP is thawed at 37°C and must be transfused within:

Accepted Answer

24 hours if kept at 1–6°C

Answer

Thawed FFP relabeled as 'thawed plasma' can be stored at 1–6°C for up to 5 days; if used as FFP it should be infused within 24 hours.

Question 5

The Kidd blood group system is clinically significant primarily because Kidd antibodies:

Accepted Answer

Cause dosage and are often transient, leading to delayed hemolytic reactions

Answer

Kidd antibodies show dosage, fall below detectable levels quickly, and can cause severe delayed hemolytic transfusion reactions when the antigen is re-encountered.

Medical Laboratory Technician Exam Practice Test

Medical Laboratory Technician Exam Practice Test

Medical Laboratory Technician Exam Blood Bank and Transfusion 3