Blood Bank and Transfusion Flashcards
7 cards from real Medical Laboratory Technician Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Blood Bank and Transfusion flashcards as text
A patient with anti-K antibody needs a transfusion. Which percentage of random donors are Kell-negative?
Answer: About 91%
Approximately 91% of the population is K-negative (kk genotype), making compatible blood relatively easy to find.
Which phenotype is known as the 'Bombay phenotype' and lacks H antigen on red cells?
Answer: Oh (hh)
The Bombay phenotype (Oh) lacks the H antigen due to homozygous h/h, making individuals incompatible with all ABO groups.
A DAT is positive with anti-IgG but negative with anti-C3d. This pattern is most consistent with:
Answer: Drug-induced immune hemolysis (drug adsorption)
Drug adsorption (hapten) mechanism coats RBCs with IgG drug antibodies, yielding a DAT positive only with anti-IgG reagent.
Which irradiation dose is used for blood components to prevent transfusion-associated graft-versus-host disease (TA-GvHD)?
Answer: 2,500 cGy minimum
A minimum of 2,500 cGy (25 Gy) delivered to the midplane inactivates donor lymphocytes and prevents TA-GvHD.
In an antibody identification panel, an antibody reacts with all cells except those negative for a single antigen. This pattern indicates:
Answer: A single alloantibody to that antigen
Reactivity with all antigen-positive cells and non-reactivity with antigen-negative cells defines a single alloantibody to that antigen.
Platelets stored at room temperature (20–24°C) have a maximum shelf life of:
Answer: 7 days with pathogen reduction
Standard platelets expire in 5 days, but pathogen-reduced platelets with secondary rapid testing may be stored up to 7 days per FDA guidance.
A neonate is found to have anti-c in maternal serum. Which Rh phenotype should be selected for exchange transfusion?
Answer: R1R1 (CDe/CDe)
R1R1 (CDe/CDe) units are c-negative and will not be destroyed by maternal anti-c crossing the placenta.