SBB Human Blood Groups Exam | Actual Questions and
Answers Latest Updated 2026/2027 (Graded A+)
•
How would Ulex europaeus react with O, A, A2, B, A2B, A1B RBCs?
- ✔✔O>A2>B>A2B>A1>A1B
•
How could you distinguish serologically A1, A2 and A3
- ✔✔Dolichos biflorus can will react with A1 and not A2. A3 yields mixed field reactions with
anti-A and anti-A,B
•
What is the correct order of type of RBCs to transfuse in an AB patient when AB RBCs are not
available? Why?
- ✔✔A, B, O; the residual anti-B in A RBCs is less immunogenic than the residual anti-A in B
RBCs
•
What type of RBCs would you transfuse to a patient with anti-G
- ✔✔RBCs transfused must lack the D and C antigens
•
Can you detect a weak D using Gel Technology?
- ✔✔No, because there is no washing phase
•
Can an Rh positive father and Rh positive mother yield an Rh negative child
- ✔✔Yes, if both parents are heterozygous for the D gene. Inheritance is autosomal
recessive
•
What type of RBCs in regards to Rh phenotype would you transfuse in a patient with anti-f
- ✔✔RBCs should be negative for the c and e antigens
•
How could you solve an ABO discrepancy where Anti-M was causing aberrant results in reverse
grouping when the forward type is consistent with A blood group and reverse as O?
- ✔✔Treat A1 cells with ficin to denature the M antigen, repeat reverse grouping with
ficin-treated A1 cells.
•
Why do you see an anti-N like specificity in dialysis patients?
- ✔✔Formaldehyde induced antibody to 'N' due to formaldehyde used in dialysis
procedures.
, •
A patient types as follows: anti-A=4+, Anti-B=1+, A1 Cells=2+, B cells=4+. The ABO discrepancy led to
suspicion of a possible cold autoantibody based on patient histopry and diagnosis. RESt was used in
an attept to adsorb the autoantobidy. The type was repeated with adsorbed plasma Anit-A=4+,
Anti-B=0, A1 cells=0, B cells=0. What could be the cause of this discrepancy?
- ✔✔Anti-B was adsorbed out with RESt.
•
What enzyme may be useful in distinguishing anti-Ge2?
- ✔✔papain
•
The beta 1-3 linkage between galactose and N-acetylglucosamine is found in?
- ✔✔secretions
•
Represents Type II chain
- ✔✔Beta 1-4 linkage between galactose and N acetyl glucosamine
•
Represents decreasing concentrations of H antigen on RBCs
- ✔✔O>A2>B>A2B>A1>A1B
•
The ABO genes are located on what chromosome
- ✔✔Chromosome 9
•
Which glycosyltransferase is needed before A and B antigens are formed?
- ✔✔L-fucosyltransferase
•
Which reflects the A3 subgroup
- ✔✔mixed field reactions with Anti-A and Anti-A,B.
•
Which fo the following reflects the A el subgroup?
- ✔✔Positive reactions with Anti-H
•
What clinical condition may yield positive reactions with Anti-A, negative with Anti-B, negative with A1
and B cells.
- ✔✔hypogammaglobulinemia
•
What differentiates a Bombay anti-H from an anti-H cold agglutinin?
- ✔✔reactivity at body temperature.
Answers Latest Updated 2026/2027 (Graded A+)
•
How would Ulex europaeus react with O, A, A2, B, A2B, A1B RBCs?
- ✔✔O>A2>B>A2B>A1>A1B
•
How could you distinguish serologically A1, A2 and A3
- ✔✔Dolichos biflorus can will react with A1 and not A2. A3 yields mixed field reactions with
anti-A and anti-A,B
•
What is the correct order of type of RBCs to transfuse in an AB patient when AB RBCs are not
available? Why?
- ✔✔A, B, O; the residual anti-B in A RBCs is less immunogenic than the residual anti-A in B
RBCs
•
What type of RBCs would you transfuse to a patient with anti-G
- ✔✔RBCs transfused must lack the D and C antigens
•
Can you detect a weak D using Gel Technology?
- ✔✔No, because there is no washing phase
•
Can an Rh positive father and Rh positive mother yield an Rh negative child
- ✔✔Yes, if both parents are heterozygous for the D gene. Inheritance is autosomal
recessive
•
What type of RBCs in regards to Rh phenotype would you transfuse in a patient with anti-f
- ✔✔RBCs should be negative for the c and e antigens
•
How could you solve an ABO discrepancy where Anti-M was causing aberrant results in reverse
grouping when the forward type is consistent with A blood group and reverse as O?
- ✔✔Treat A1 cells with ficin to denature the M antigen, repeat reverse grouping with
ficin-treated A1 cells.
•
Why do you see an anti-N like specificity in dialysis patients?
- ✔✔Formaldehyde induced antibody to 'N' due to formaldehyde used in dialysis
procedures.
, •
A patient types as follows: anti-A=4+, Anti-B=1+, A1 Cells=2+, B cells=4+. The ABO discrepancy led to
suspicion of a possible cold autoantibody based on patient histopry and diagnosis. RESt was used in
an attept to adsorb the autoantobidy. The type was repeated with adsorbed plasma Anit-A=4+,
Anti-B=0, A1 cells=0, B cells=0. What could be the cause of this discrepancy?
- ✔✔Anti-B was adsorbed out with RESt.
•
What enzyme may be useful in distinguishing anti-Ge2?
- ✔✔papain
•
The beta 1-3 linkage between galactose and N-acetylglucosamine is found in?
- ✔✔secretions
•
Represents Type II chain
- ✔✔Beta 1-4 linkage between galactose and N acetyl glucosamine
•
Represents decreasing concentrations of H antigen on RBCs
- ✔✔O>A2>B>A2B>A1>A1B
•
The ABO genes are located on what chromosome
- ✔✔Chromosome 9
•
Which glycosyltransferase is needed before A and B antigens are formed?
- ✔✔L-fucosyltransferase
•
Which reflects the A3 subgroup
- ✔✔mixed field reactions with Anti-A and Anti-A,B.
•
Which fo the following reflects the A el subgroup?
- ✔✔Positive reactions with Anti-H
•
What clinical condition may yield positive reactions with Anti-A, negative with Anti-B, negative with A1
and B cells.
- ✔✔hypogammaglobulinemia
•
What differentiates a Bombay anti-H from an anti-H cold agglutinin?
- ✔✔reactivity at body temperature.
