Blood Bank ASCP EXAM Questions
and Correct Answers Latest Actual
Exam| Brand New Version 2025
How is an individual with genotype Dce/dce classified?
A. Rh positive
B. Rh negative
C. Rhnull
D. Total Rh CORRECT ANSWER: This individual has the D antigen and is classified
as Rh positive. Any genotype containing the D antigen will be considered Rh positive
If a patient has a positive direct antiglobulin test, should you perform a weak D test on
the cells?
A. No, the cells are already coated with antibody
B. No, the cells are Rhnull
C. Yes, the immunoglobulin will not interfere with the test
D. Yes, Rh reagents are enhanced in protein media CORRECT ANSWER: No, the cells
are already coated with antibody.
If a person has a positive DAT, the red cells are coated with immunoglobulin (anti-IgG
and anti- C3d, or both). If a test for weak D were performed, the test would yield
positive results independent of the presence or absence of the D antigen on the red cells.
Which donor unit is selected for a recipient with anti-c?
A. r´r
B. R0R1
C. R2r´
D. r´ry CORRECT ANSWER: D. r´ry
Which genotype usually shows the strongest reaction with anti-D?
A. DCE/DCE
B. Dce/dCe
C. D-/D-
D. -CE/-ce CORRECT ANSWER: C. D-/D-
The phenotype that results from D-/D- is classified as enhanced D because it shows a
stronger reaction than expected with anti-D. Such cells have a greater amount of D
antigen than normal. This is thought to result from a larger quantity of precursors being
available to the D genes because there is no competition from other Rh genes
Why is testing for Rh antigens and antibodies different from ABO testing? CORRECT
ANSWER: ABO reactions are primarily due to IgM antibodies and usually occur at
,room temperature; Rh antibodies are IgG and agglutination usually requires a 37°C
incubation and enhancement media
Testing reveals a weak D that reacts 1+ after indirect antiglobulin testing (IAT). How is
this result classified? CORRECT ANSWER: Blood tested for weak D that shows 1+
reaction after IAT is classified as Rh positive. The weak D designation is not noted in the
reporting of the result.
What is one possible genotype for a patient who develops anti-C antibody?
A. R1r
B. R1R1
C. r´r
D. rr CORRECT ANSWER: D. rr
Only rr (dce/dce) does not contain C antigen. A person will form alloantibodies only to
the antigens he or she lacks.
A patient developed a combination of Rh antibodies: anti-C, anti-E, and anti-D. Can
compatible blood be found for this patient?
A. It is almost impossible to find blood lacking the C, E, and D antigens
B. rr blood could be used without causing a problem
C. R0R0 may be used because it lacks all three antigens
D. Although rare, ryr blood may be obtained from close relatives of the patient
CORRECT ANSWER: B. rr blood could be used without causing a problem
The genotype rr (dce/dce) lacks D, C, and E antigens and would be suitable for an
individual who has developed antibodies to all three antigens. This is the most common
Rh-negative genotype and is found in nearly 14% of White blood donors.
A patient tests positive for weak D but also appears to have anti-D in his serum. What
may be the problem?
A. Mixup of samples or testing error
B. Most weak D individuals make anti-D
C. The problem could be due to a disease state
D. A D mosaic may make antibodies to missing antigen parts CORRECT ANSWER:
D. A D mosaic may make antibodies to missing antigen parts
Which offspring is not possible from a mother who is R1R2 and a father who is R1r?
A. DcE/DcE
B. Dce/DCe
C. DcE/DCe
D. Dce/dce CORRECT ANSWER: A. DcE/DcE
DcE/DcE (R2R2) is not possible because R2 can be inherited only from the mother and
is not present in the father.
,Why is testing a pregnant woman for weak D not required? CORRECT ANSWER: An
Rh-positive fetus may yield false positive results in a fetal maternal bleed
If a weak D test is performed on a pregnant woman with no previous history, a false-
positive weak D test may result from the presence of fetal blood if the fetus is Rh
positive. A pregnant woman with weak D may be given Rh immune globulin without any
harmful consequences. Therefore, weak D testing of pregnant women is not necessary.
What antibodies could an R1R1 make if exposed to R2R2 blood? CORRECT
ANSWER: The R1R1 (DCe/DCe) individual does not have the E or c antigen, and could
make anti-E and anti-c antibodies when exposed to R2R2 cells (DcE/DcE).
What does the genotype —/— represent in the Rh system?
A. Rh negative
B. D mosaic
C. Rhnull
D. Total Rh CORRECT ANSWER: Rh null
A person who is Rhnull shows no Rh antigens on his or her RBCs. Loss of Rh antigens is
very unlikely to happen because Rh antigens are integral parts of the RBC membrane.
The Rhnull phenotype can result from either genetic suppression of the Rh genes or
inheritance of amorphic genes at the Rh locus.
What techniques are necessary for weak D testing?
A. Saline + 22°C incubation
B. Albumin or LISS + 37°C incubation
C. Saline + 37°C incubation
D. 37°C incubation + IAT CORRECT ANSWER: D. 37°C incubation + IAT
Weak D testing requires both 37°C incubation and the IAT procedure. Anti-D is an IgG
antibody, and attachment of the D antigen is optimized at warmer temperatures.
Antihuman globulin in the IAT phase facilitates lattice formation by binding to the
antigen-antibody complexes.
Weak D procedure CORRECT ANSWER: Prepare a washed, 3% suspension of patient
cells, and set up the D and DC (Rh Control) tubes, if not already done. (SEE ABO/Rh
TYPING PROCEDURE)
Record the D and DC immediate spin results. If the Rh test is negative, continue with
step 3.
Incubate both tubes at 37oC for 15 to 30 minutes.
Centrifuge and read for agglutination as usual. If the Rh test is negative, continue with
step 5.
Wash both tubes 3-4 times with saline.
, Immediately after the last wash, add one drop Coombs serum to each tube and
centrifuge in the serofuge the time appropriate for the Coombs spin calibration.
Immediately resuspend gently and examine for agglutination using the lighted
agglutination viewer.
Record results in the appropriate column on the worksheet
Confirm all negative results by adding one drop Coombs control cells to all tubes
showing no agglutination and centrifuge 15-30 seconds at high speed in the serofuge.
Gently resuspend and examine for agglutination. Agglutination should be present in this
step or the test is invalid.
Weak D Results Interpretation CORRECT ANSWER: A negative result in the
immediate spin phase but agglutination in the D tube following incubation (with no
agglutination in the DC tube) indicates a positive test for weak D. Lack of agglutination
is a negative test and the patient is considered truly D negative. Agglutination in the DC
tube invalidates the test.
A true weak D should give at least a 2+ positive result. Weaker results may be due to
mixed field agglutination in an Rh negative individual who received Rh positive blood,
or vice-versa. Obtain a recent transfusion history on patients who give inconclusive
weak D results
A patient types as AB and appears to be Rh positive on slide typing. What additional
tests should be performed for tube typing?
A. Rh negative control
B. Direct antiglobulin test (DAT)
C. Low-protein Rh antisera
D. No additional testing is needed CORRECT ANSWER: An Rh-negative control
(patient cells in saline or
6% albumin) should be run if a sample appears to be AB positive. The ABO test serves as
the Rh control for other ABO types.
What is one possible genotype for a patient who develops anti-C antibody?
A. R1r
B. R1R1
C. r´r
D. rr CORRECT ANSWER: D. rr
Which of the following distinguishes A1 from A2 blood groups?
A. A2 antigen will not react with anti-A, A1 will react strongly (4+)
B. An A2 person may form anti-A1; an A1 person will not form anti-A1
C. An A1 person may form anti-A2, an A2 person will not form anti-A1
D. A2 antigen will not react with anti-A from a nonimmunized donor; A1 will react with
any anti-A CORRECT ANSWER: B. An A2 person may form anti-A1; an A1 person
will not form anti-A1
and Correct Answers Latest Actual
Exam| Brand New Version 2025
How is an individual with genotype Dce/dce classified?
A. Rh positive
B. Rh negative
C. Rhnull
D. Total Rh CORRECT ANSWER: This individual has the D antigen and is classified
as Rh positive. Any genotype containing the D antigen will be considered Rh positive
If a patient has a positive direct antiglobulin test, should you perform a weak D test on
the cells?
A. No, the cells are already coated with antibody
B. No, the cells are Rhnull
C. Yes, the immunoglobulin will not interfere with the test
D. Yes, Rh reagents are enhanced in protein media CORRECT ANSWER: No, the cells
are already coated with antibody.
If a person has a positive DAT, the red cells are coated with immunoglobulin (anti-IgG
and anti- C3d, or both). If a test for weak D were performed, the test would yield
positive results independent of the presence or absence of the D antigen on the red cells.
Which donor unit is selected for a recipient with anti-c?
A. r´r
B. R0R1
C. R2r´
D. r´ry CORRECT ANSWER: D. r´ry
Which genotype usually shows the strongest reaction with anti-D?
A. DCE/DCE
B. Dce/dCe
C. D-/D-
D. -CE/-ce CORRECT ANSWER: C. D-/D-
The phenotype that results from D-/D- is classified as enhanced D because it shows a
stronger reaction than expected with anti-D. Such cells have a greater amount of D
antigen than normal. This is thought to result from a larger quantity of precursors being
available to the D genes because there is no competition from other Rh genes
Why is testing for Rh antigens and antibodies different from ABO testing? CORRECT
ANSWER: ABO reactions are primarily due to IgM antibodies and usually occur at
,room temperature; Rh antibodies are IgG and agglutination usually requires a 37°C
incubation and enhancement media
Testing reveals a weak D that reacts 1+ after indirect antiglobulin testing (IAT). How is
this result classified? CORRECT ANSWER: Blood tested for weak D that shows 1+
reaction after IAT is classified as Rh positive. The weak D designation is not noted in the
reporting of the result.
What is one possible genotype for a patient who develops anti-C antibody?
A. R1r
B. R1R1
C. r´r
D. rr CORRECT ANSWER: D. rr
Only rr (dce/dce) does not contain C antigen. A person will form alloantibodies only to
the antigens he or she lacks.
A patient developed a combination of Rh antibodies: anti-C, anti-E, and anti-D. Can
compatible blood be found for this patient?
A. It is almost impossible to find blood lacking the C, E, and D antigens
B. rr blood could be used without causing a problem
C. R0R0 may be used because it lacks all three antigens
D. Although rare, ryr blood may be obtained from close relatives of the patient
CORRECT ANSWER: B. rr blood could be used without causing a problem
The genotype rr (dce/dce) lacks D, C, and E antigens and would be suitable for an
individual who has developed antibodies to all three antigens. This is the most common
Rh-negative genotype and is found in nearly 14% of White blood donors.
A patient tests positive for weak D but also appears to have anti-D in his serum. What
may be the problem?
A. Mixup of samples or testing error
B. Most weak D individuals make anti-D
C. The problem could be due to a disease state
D. A D mosaic may make antibodies to missing antigen parts CORRECT ANSWER:
D. A D mosaic may make antibodies to missing antigen parts
Which offspring is not possible from a mother who is R1R2 and a father who is R1r?
A. DcE/DcE
B. Dce/DCe
C. DcE/DCe
D. Dce/dce CORRECT ANSWER: A. DcE/DcE
DcE/DcE (R2R2) is not possible because R2 can be inherited only from the mother and
is not present in the father.
,Why is testing a pregnant woman for weak D not required? CORRECT ANSWER: An
Rh-positive fetus may yield false positive results in a fetal maternal bleed
If a weak D test is performed on a pregnant woman with no previous history, a false-
positive weak D test may result from the presence of fetal blood if the fetus is Rh
positive. A pregnant woman with weak D may be given Rh immune globulin without any
harmful consequences. Therefore, weak D testing of pregnant women is not necessary.
What antibodies could an R1R1 make if exposed to R2R2 blood? CORRECT
ANSWER: The R1R1 (DCe/DCe) individual does not have the E or c antigen, and could
make anti-E and anti-c antibodies when exposed to R2R2 cells (DcE/DcE).
What does the genotype —/— represent in the Rh system?
A. Rh negative
B. D mosaic
C. Rhnull
D. Total Rh CORRECT ANSWER: Rh null
A person who is Rhnull shows no Rh antigens on his or her RBCs. Loss of Rh antigens is
very unlikely to happen because Rh antigens are integral parts of the RBC membrane.
The Rhnull phenotype can result from either genetic suppression of the Rh genes or
inheritance of amorphic genes at the Rh locus.
What techniques are necessary for weak D testing?
A. Saline + 22°C incubation
B. Albumin or LISS + 37°C incubation
C. Saline + 37°C incubation
D. 37°C incubation + IAT CORRECT ANSWER: D. 37°C incubation + IAT
Weak D testing requires both 37°C incubation and the IAT procedure. Anti-D is an IgG
antibody, and attachment of the D antigen is optimized at warmer temperatures.
Antihuman globulin in the IAT phase facilitates lattice formation by binding to the
antigen-antibody complexes.
Weak D procedure CORRECT ANSWER: Prepare a washed, 3% suspension of patient
cells, and set up the D and DC (Rh Control) tubes, if not already done. (SEE ABO/Rh
TYPING PROCEDURE)
Record the D and DC immediate spin results. If the Rh test is negative, continue with
step 3.
Incubate both tubes at 37oC for 15 to 30 minutes.
Centrifuge and read for agglutination as usual. If the Rh test is negative, continue with
step 5.
Wash both tubes 3-4 times with saline.
, Immediately after the last wash, add one drop Coombs serum to each tube and
centrifuge in the serofuge the time appropriate for the Coombs spin calibration.
Immediately resuspend gently and examine for agglutination using the lighted
agglutination viewer.
Record results in the appropriate column on the worksheet
Confirm all negative results by adding one drop Coombs control cells to all tubes
showing no agglutination and centrifuge 15-30 seconds at high speed in the serofuge.
Gently resuspend and examine for agglutination. Agglutination should be present in this
step or the test is invalid.
Weak D Results Interpretation CORRECT ANSWER: A negative result in the
immediate spin phase but agglutination in the D tube following incubation (with no
agglutination in the DC tube) indicates a positive test for weak D. Lack of agglutination
is a negative test and the patient is considered truly D negative. Agglutination in the DC
tube invalidates the test.
A true weak D should give at least a 2+ positive result. Weaker results may be due to
mixed field agglutination in an Rh negative individual who received Rh positive blood,
or vice-versa. Obtain a recent transfusion history on patients who give inconclusive
weak D results
A patient types as AB and appears to be Rh positive on slide typing. What additional
tests should be performed for tube typing?
A. Rh negative control
B. Direct antiglobulin test (DAT)
C. Low-protein Rh antisera
D. No additional testing is needed CORRECT ANSWER: An Rh-negative control
(patient cells in saline or
6% albumin) should be run if a sample appears to be AB positive. The ABO test serves as
the Rh control for other ABO types.
What is one possible genotype for a patient who develops anti-C antibody?
A. R1r
B. R1R1
C. r´r
D. rr CORRECT ANSWER: D. rr
Which of the following distinguishes A1 from A2 blood groups?
A. A2 antigen will not react with anti-A, A1 will react strongly (4+)
B. An A2 person may form anti-A1; an A1 person will not form anti-A1
C. An A1 person may form anti-A2, an A2 person will not form anti-A1
D. A2 antigen will not react with anti-A from a nonimmunized donor; A1 will react with
any anti-A CORRECT ANSWER: B. An A2 person may form anti-A1; an A1 person
will not form anti-A1
