Harr ASCP Blood Bank Review | ABO, Rh,
Antibodies, Transfusion Reactions, Serology &
Exam Prep Q&A 1536 Questions and correct
Answers. 100%. 2025/2026.
What type of serological testing does the blood bank technologist perform when determining
the blood group of a patient?
Phenotyping
If anti-K reacts 3+ with a donor cell with a genotype KK and 2+ with a Kk cell, the antibody is
demonstrating:
Dosage
Carla expresses the blood group antigens Fya, Fyb ,and Xga. James shows expressions of none of
these antigens. What factor(s) may account for the absence of these antigens in James?
Gender and race
Which of the following statements is true?
a. An individual with the BO genotype is homozygous for B antigen
b. An individual with the BB genotype is homozygous for B antigen
c. An individual with the OO genotype is heterozygous for O antigen
d. An individual with the AB phenotype is homozygous for A and B antigens
An individual with the BB genotype is homozygous for B antigen
Which genotype is heterozygous for C?
DCe/dce
Which genotype(s) will give rise to the Bombay phenotype?
hh only
Meiosis in cell division is limited to the ova and sperm producing four gametes containing what
complement of DNA?
1N
A cell that is not actively dividing is said to be in:
,Interphase
Which of the following describes the expression of most blood group antigens?
Codominant
What blood type is not possible for an offspring of an AO and BO mating?
All are possible
The alleged father of a child in a disputed case of paternity is blood group AB. The mother is
group O and the child is group O. What type of exclusion is this?
Indirect/secondary/second order
If the frequency of gene Y is 0.4 and the frequency of gene Z is 0.5, one would expect that they
should occur together 0.2 (20%) of the time. In actuality,they are found together 32% of the
time. This is an example of:
Linkage disequilibrium
In the Hardy-Weinberg formula, p^2 represents:
The homozygous population of one allele
In this type of inheritance, the father carries the trait on his X chromosome. He has no sons with
the trait because he passed his Y chromosome to his sons; however, all his daughters will
express the trait.
X-linked dominant
Why do IgM antibodies, such as those formed against the ABO antigens, have the ability to
directly agglutinate red blood cells (RBCs) and cause visible agglutination?
IgM antibodies are larger molecules and have the ability to bind more antigen
Which of the following enhancement mediums decreases the zeta potential, allowing antibody
and antigen to come closer together?
LISS
This type of antibody response is analogous to an anamnestic antibody reaction.
Secondary
Which antibodies to a component of complement are contained in the rabbit polyspecific
antihuman globulin reagent for detection of in vivo sensitization?
Anti-IgG and anti-C3d
,Which of the following distinguishes A1 from A2 blood groups?
An A2 person may form anti-A1; an A1 person will not form anti-A1
A patient's serum is incompatible with O cells. The patient RBCs give a negative reaction to anti-
H lectin. What is the most likely cause of these results?
The patient may be a Bombay
What antibodies are formed by a Bombay individual?
Anti-A, B, and H
Acquired B antigens have been found in:
Group A persons
Blood is crossmatched on an A positive person with a negative antibody screen. The patient
received a transfusion of A positive RBCs 3 years ago. The donors chosen for crossmatch were A
positive. The crossmatch was run on the Ortho Provue and yielded 3+ incompatibility. How can
these results be explained?
The patient is an A2 with anti-A1
A patient's red cells forward as group O, serum agglutinates B cells (4+) only. Your next step
would be:
Incubate washed red cells with anti-A1 and anti-A,B for 30 minutes at room temperature
Which typing results are most likely to occur when a patient has an acquired B antigen?
Anti-A 4+, anti-B 1+, A1 cells neg, B cells 4+
Which blood group has the least amount of H antigen?
A1B
What type RBCs can be transfused to an A2 person with anti-A1?
A or O
What should be done if all forward and reverse ABO results as well as the autocontrol are
positive?
Wash the cells with warm saline, autoadsorb the serum at 4°C
What should be done if all forward and reverse ABO results are negative?
Incubate at 22°C or 4°C to enhance weak expression
, N-acetyl-D-galactosamine is the immunodominant carbohydrate that reacts with:
Dolichos biflorus
A stem cell transplant patient was retyped when she was transferred from another hospital.
What is the most likely cause of the following results?
Patient cells: Anti-A, neg; Anti-B, 4+
Patient serum: A1 cells, neg; B cells, neg
Immunodeficiency
What reaction would be the same for an A1 and an A2 person?
Positive reaction with anti-A,B
A female patient at 28 weeks' gestation yields the following results:
Patient cells: Anti-A 3+; Anti-B 4+
Patient serum: A1 cells, neg; B cells 1+; O cells, 1+
Alloantibody in patient serum
Which condition would most likely be responsible for the following typing results?
Patient cells: Anti-A, neg; Anti-B, neg
Patient serum: A1 cells, neg; B cells, 4+
Weak or excessive antigen(s)
Which of the following results is most likely discrepant?
Anti-A, neg; Anti-B, 4+
A1 cells, neg; B cells, neg
Negative A1 cells
A 61-year-old male with a history of multiple myeloma had a stem cell transplant 3 years ago.
The donor was O positive and the recipient was B positive. He is admitted to a community
hospital for fatigue and nausea. Typing results reveal the following:
Anti-A = 0; Anti-B =0; Anti-A,B = 0; Anti-D = 4+; A1 cells = 4+; B cells = 0
How would you report this type?
Undetermined
A complete Rh typing for antigens C, c, D, E, and e revealed negative results for C, D, and E. How
is the individual designated?
Rh negative
How is an individual with genotype Dce/dce classified?
Antibodies, Transfusion Reactions, Serology &
Exam Prep Q&A 1536 Questions and correct
Answers. 100%. 2025/2026.
What type of serological testing does the blood bank technologist perform when determining
the blood group of a patient?
Phenotyping
If anti-K reacts 3+ with a donor cell with a genotype KK and 2+ with a Kk cell, the antibody is
demonstrating:
Dosage
Carla expresses the blood group antigens Fya, Fyb ,and Xga. James shows expressions of none of
these antigens. What factor(s) may account for the absence of these antigens in James?
Gender and race
Which of the following statements is true?
a. An individual with the BO genotype is homozygous for B antigen
b. An individual with the BB genotype is homozygous for B antigen
c. An individual with the OO genotype is heterozygous for O antigen
d. An individual with the AB phenotype is homozygous for A and B antigens
An individual with the BB genotype is homozygous for B antigen
Which genotype is heterozygous for C?
DCe/dce
Which genotype(s) will give rise to the Bombay phenotype?
hh only
Meiosis in cell division is limited to the ova and sperm producing four gametes containing what
complement of DNA?
1N
A cell that is not actively dividing is said to be in:
,Interphase
Which of the following describes the expression of most blood group antigens?
Codominant
What blood type is not possible for an offspring of an AO and BO mating?
All are possible
The alleged father of a child in a disputed case of paternity is blood group AB. The mother is
group O and the child is group O. What type of exclusion is this?
Indirect/secondary/second order
If the frequency of gene Y is 0.4 and the frequency of gene Z is 0.5, one would expect that they
should occur together 0.2 (20%) of the time. In actuality,they are found together 32% of the
time. This is an example of:
Linkage disequilibrium
In the Hardy-Weinberg formula, p^2 represents:
The homozygous population of one allele
In this type of inheritance, the father carries the trait on his X chromosome. He has no sons with
the trait because he passed his Y chromosome to his sons; however, all his daughters will
express the trait.
X-linked dominant
Why do IgM antibodies, such as those formed against the ABO antigens, have the ability to
directly agglutinate red blood cells (RBCs) and cause visible agglutination?
IgM antibodies are larger molecules and have the ability to bind more antigen
Which of the following enhancement mediums decreases the zeta potential, allowing antibody
and antigen to come closer together?
LISS
This type of antibody response is analogous to an anamnestic antibody reaction.
Secondary
Which antibodies to a component of complement are contained in the rabbit polyspecific
antihuman globulin reagent for detection of in vivo sensitization?
Anti-IgG and anti-C3d
,Which of the following distinguishes A1 from A2 blood groups?
An A2 person may form anti-A1; an A1 person will not form anti-A1
A patient's serum is incompatible with O cells. The patient RBCs give a negative reaction to anti-
H lectin. What is the most likely cause of these results?
The patient may be a Bombay
What antibodies are formed by a Bombay individual?
Anti-A, B, and H
Acquired B antigens have been found in:
Group A persons
Blood is crossmatched on an A positive person with a negative antibody screen. The patient
received a transfusion of A positive RBCs 3 years ago. The donors chosen for crossmatch were A
positive. The crossmatch was run on the Ortho Provue and yielded 3+ incompatibility. How can
these results be explained?
The patient is an A2 with anti-A1
A patient's red cells forward as group O, serum agglutinates B cells (4+) only. Your next step
would be:
Incubate washed red cells with anti-A1 and anti-A,B for 30 minutes at room temperature
Which typing results are most likely to occur when a patient has an acquired B antigen?
Anti-A 4+, anti-B 1+, A1 cells neg, B cells 4+
Which blood group has the least amount of H antigen?
A1B
What type RBCs can be transfused to an A2 person with anti-A1?
A or O
What should be done if all forward and reverse ABO results as well as the autocontrol are
positive?
Wash the cells with warm saline, autoadsorb the serum at 4°C
What should be done if all forward and reverse ABO results are negative?
Incubate at 22°C or 4°C to enhance weak expression
, N-acetyl-D-galactosamine is the immunodominant carbohydrate that reacts with:
Dolichos biflorus
A stem cell transplant patient was retyped when she was transferred from another hospital.
What is the most likely cause of the following results?
Patient cells: Anti-A, neg; Anti-B, 4+
Patient serum: A1 cells, neg; B cells, neg
Immunodeficiency
What reaction would be the same for an A1 and an A2 person?
Positive reaction with anti-A,B
A female patient at 28 weeks' gestation yields the following results:
Patient cells: Anti-A 3+; Anti-B 4+
Patient serum: A1 cells, neg; B cells 1+; O cells, 1+
Alloantibody in patient serum
Which condition would most likely be responsible for the following typing results?
Patient cells: Anti-A, neg; Anti-B, neg
Patient serum: A1 cells, neg; B cells, 4+
Weak or excessive antigen(s)
Which of the following results is most likely discrepant?
Anti-A, neg; Anti-B, 4+
A1 cells, neg; B cells, neg
Negative A1 cells
A 61-year-old male with a history of multiple myeloma had a stem cell transplant 3 years ago.
The donor was O positive and the recipient was B positive. He is admitted to a community
hospital for fatigue and nausea. Typing results reveal the following:
Anti-A = 0; Anti-B =0; Anti-A,B = 0; Anti-D = 4+; A1 cells = 4+; B cells = 0
How would you report this type?
Undetermined
A complete Rh typing for antigens C, c, D, E, and e revealed negative results for C, D, and E. How
is the individual designated?
Rh negative
How is an individual with genotype Dce/dce classified?
