SBB ACTUAL TEST QUESTIONS WITH
COMPLETE ANSWER KEY
●● How could you distinguish serologically A1, A2 and A3
Answer: 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?
Answer: 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
Answer: RBCs transfused must lack the D and C antigens
●● Can you detect a weak D using Gel Technology?
Answer: No, because there is no washing phase
●● Can an Rh positive father and Rh positive mother yield an Rh
negative child
Answer: 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
Answer: 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?
Answer: 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?
Answer: 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?
Answer: Anti-B was adsorbed out with RESt.
●● What enzyme may be useful in distinguishing anti-Ge2?
Answer: papain
, ●● The beta 1-3 linkage between galactose and N-acetylglucosamine is
found in?
Answer: secretions
●● Represents Type II chain
Answer: Beta 1-4 linkage between galactose and N acetyl glucosamine
●● Represents decreasing concentrations of H antigen on RBCs
Answer: O>A2>B>A2B>A1>A1B
●● The ABO genes are located on what chromosome
Answer: Chromosome 9
●● Which glycosyltransferase is needed before A and B antigens are
formed?
Answer: L-fucosyltransferase
●● Which reflects the A3 subgroup
Answer: mixed field reactions with Anti-A and Anti-A,B.
●● Which fo the following reflects the A el subgroup?
Answer: Positive reactions with Anti-H
COMPLETE ANSWER KEY
●● How could you distinguish serologically A1, A2 and A3
Answer: 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?
Answer: 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
Answer: RBCs transfused must lack the D and C antigens
●● Can you detect a weak D using Gel Technology?
Answer: No, because there is no washing phase
●● Can an Rh positive father and Rh positive mother yield an Rh
negative child
Answer: 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
Answer: 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?
Answer: 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?
Answer: 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?
Answer: Anti-B was adsorbed out with RESt.
●● What enzyme may be useful in distinguishing anti-Ge2?
Answer: papain
, ●● The beta 1-3 linkage between galactose and N-acetylglucosamine is
found in?
Answer: secretions
●● Represents Type II chain
Answer: Beta 1-4 linkage between galactose and N acetyl glucosamine
●● Represents decreasing concentrations of H antigen on RBCs
Answer: O>A2>B>A2B>A1>A1B
●● The ABO genes are located on what chromosome
Answer: Chromosome 9
●● Which glycosyltransferase is needed before A and B antigens are
formed?
Answer: L-fucosyltransferase
●● Which reflects the A3 subgroup
Answer: mixed field reactions with Anti-A and Anti-A,B.
●● Which fo the following reflects the A el subgroup?
Answer: Positive reactions with Anti-H
