ASCP Blood Bank exam Questions with Correct
Answers
Define dosage Correct Answer-Dosage is defined as an antibody
reacting stronger with homozygous cells (such as KK) than with
heterozygous cells (Kk)
List the antigens that commonly show dosage? Correct Answer-Kell.
M.
N.
S, little s.
F.y.a, F.y.b
J.k.a, J.k.b.
Antigens of the Rh system.
Is the Duffy antigens F.y.a and F.y.b more prevalent in African
Americans or in whites? Correct Answer-In African Americans.
70% African Americans and it is very rare in whites.
What does the term heterozygous mean? Correct Answer-A diploid
organism is heterozygous at a gene locus when its cells contain two
different alleles of a gene. The cell or organism is called a heterozygote
specifically for the allele in question, and therefore, heterozygosity
refers to a specific genotype.
,What distinguishes A1 from A2 blood groups? Correct Answer-An A2
person may form anti-A1, but an A1 person will not form anti-A1.
What is the only A.B.O phenotype that is incompatible with O cells.
Correct Answer-Bombay.
The red cells of Bombay show a negative reaction to anti-H because the
cells contain no H substance.
A Bombay individual has a phenotype little hh and will type as group O.
What antibodies are formed by an Bombay individual? Correct Answer-
Anti-A, Anti-B, Anti-H.
Because a Bombay individual has three antibodies, the only compatible
blood must be from another Bombay donor.
Acquired B antigens have been found in what type of person? Correct
Answer-A-persons.
Is Acquired B phenotype a transient condition? Correct Answer-Yes,
Over time, when the root cause of the bacterial enzyme removal of the
acetyl group is resolved, a patient's blood type will no longer show an
acquired B antigen.
What causes Acquired B phenotype. Correct Answer-Acquired B occurs
when the RBCs from a blood group A patient come in contact with
bacterial enzymes known as "deacetylases" carried by bacteria that live
in the colon - typically gram-negative rods.
, What is Acquired B usually associated with? Correct Answer-colorectal
malignancy, gastrointestinal obstruction, or gram-negative sepsis -where
those bacteria can contact the RBCs.
What does a strong reaction in reverse grouping suggest when it doesn't
match the forward grouping? Correct Answer-That the discrepancy is in
forward grouping.
What should be done if a strong reaction is seen in the reverse that
doesn't match the forward? Correct Answer-Incubate washed red cells at
room temperature with anti-A and anti-A,B which will enhance
reactions.
What typing results are most likely to occur when a patient has an
acquired B antigen? Correct Answer-Anti-A-4+
Anti-B-1+
A1 cells-negative
B cells-4+
Which blood group has the least amount of H antigen? Correct Answer-
A1B.
This is due to both A and B epitope present on red cells compromising
the availability of H epitope. A1B cells will yield weak reactions with
anti H lectin.
Answers
Define dosage Correct Answer-Dosage is defined as an antibody
reacting stronger with homozygous cells (such as KK) than with
heterozygous cells (Kk)
List the antigens that commonly show dosage? Correct Answer-Kell.
M.
N.
S, little s.
F.y.a, F.y.b
J.k.a, J.k.b.
Antigens of the Rh system.
Is the Duffy antigens F.y.a and F.y.b more prevalent in African
Americans or in whites? Correct Answer-In African Americans.
70% African Americans and it is very rare in whites.
What does the term heterozygous mean? Correct Answer-A diploid
organism is heterozygous at a gene locus when its cells contain two
different alleles of a gene. The cell or organism is called a heterozygote
specifically for the allele in question, and therefore, heterozygosity
refers to a specific genotype.
,What distinguishes A1 from A2 blood groups? Correct Answer-An A2
person may form anti-A1, but an A1 person will not form anti-A1.
What is the only A.B.O phenotype that is incompatible with O cells.
Correct Answer-Bombay.
The red cells of Bombay show a negative reaction to anti-H because the
cells contain no H substance.
A Bombay individual has a phenotype little hh and will type as group O.
What antibodies are formed by an Bombay individual? Correct Answer-
Anti-A, Anti-B, Anti-H.
Because a Bombay individual has three antibodies, the only compatible
blood must be from another Bombay donor.
Acquired B antigens have been found in what type of person? Correct
Answer-A-persons.
Is Acquired B phenotype a transient condition? Correct Answer-Yes,
Over time, when the root cause of the bacterial enzyme removal of the
acetyl group is resolved, a patient's blood type will no longer show an
acquired B antigen.
What causes Acquired B phenotype. Correct Answer-Acquired B occurs
when the RBCs from a blood group A patient come in contact with
bacterial enzymes known as "deacetylases" carried by bacteria that live
in the colon - typically gram-negative rods.
, What is Acquired B usually associated with? Correct Answer-colorectal
malignancy, gastrointestinal obstruction, or gram-negative sepsis -where
those bacteria can contact the RBCs.
What does a strong reaction in reverse grouping suggest when it doesn't
match the forward grouping? Correct Answer-That the discrepancy is in
forward grouping.
What should be done if a strong reaction is seen in the reverse that
doesn't match the forward? Correct Answer-Incubate washed red cells at
room temperature with anti-A and anti-A,B which will enhance
reactions.
What typing results are most likely to occur when a patient has an
acquired B antigen? Correct Answer-Anti-A-4+
Anti-B-1+
A1 cells-negative
B cells-4+
Which blood group has the least amount of H antigen? Correct Answer-
A1B.
This is due to both A and B epitope present on red cells compromising
the availability of H epitope. A1B cells will yield weak reactions with
anti H lectin.
