Blood Bank Antibody Screening: Techniques and Reagent Use

1. What is the purpose of an antibody screen?

To determine cholesterol levels.

To detect unexpected antibodies to red cell antigens.

To assess insulin levels in the blood.

To measure white blood cell count.

2. What does a negative antibody screen indicate?

That the test results are inconclusive.

That there are no detectable antibodies in that sample

That the antibodies present are a cause for concern.

That the sample contains a high level of antibodies.

A negative antibody screen indicates the absence of detectable antibodies in the sample, which can be a normal finding depending on the context of the test.

Explanation

A negative antibody screen indicates the absence of detectable antibodies in the sample, which can be a normal finding depending on the context of the test.

3. What would results look like if you tried to do an antigen type on a recently transfused patient?

Mixed field agglutination

Negative agglutination

Partial agglutination

Complete agglutination

When performing an antigen type on a recently transfused patient, the results may show a mixed field agglutination due to the presence of both the patient's and the donor's red blood cells.

Explanation

When performing an antigen type on a recently transfused patient, the results may show a mixed field agglutination due to the presence of both the patient's and the donor's red blood cells.

4. What is the frequency of the allele Cw?

15%

2%

5%

10%

The correct answer is 2%, as the ag freq for Cw is 2% in this context.

Explanation

The correct answer is 2%, as the ag freq for Cw is 2% in this context.

5. At what phase do S, s, and U antibodies react at?

IgG 37

IgM 12

IgE 68

IgA 25

Antibodies S, s, and U typically react at the IgG phase 37.

Explanation

Antibodies S, s, and U typically react at the IgG phase 37.

6. At what phase do Kell ab react at?

IgE 45

IgM 24

IgG 37

IgA 12

Kell antibodies react at IgG 37 phase. IgA 12, IgM 24, and IgE 45 are incorrect answers as Kell antibodies do not react at these phases.

Explanation

Kell antibodies react at IgG 37 phase. IgA 12, IgM 24, and IgE 45 are incorrect answers as Kell antibodies do not react at these phases.

7. At what phase do Kidd antibodies react?

IgM

IgG 40

IgA

IgG 37

Kidd antibodies react during the IgG 37 phase, specifically targeting the Kidd blood group system. IgM, IgG 40, and IgA are not phases in which Kidd antibodies typically react.

Explanation

Kidd antibodies react during the IgG 37 phase, specifically targeting the Kidd blood group system. IgM, IgG 40, and IgA are not phases in which Kidd antibodies typically react.

8. At what phase do Duffy ab react?

IgA 45

IgM 21

IgG 37

IgE 10

Duffy antibodies react during IgG 37 phase based on the correct answer provided.

Explanation

Duffy antibodies react during IgG 37 phase based on the correct answer provided.

9. At what phase do Rh antibodies react best at?

IgM

IgA

IgG 37/AHG

IgE

Rh antibodies react best at the IgG 37/AHG phase because of their specificity and ability to trigger the formation of antigen-antibody complexes leading to agglutination.

Explanation

Rh antibodies react best at the IgG 37/AHG phase because of their specificity and ability to trigger the formation of antigen-antibody complexes leading to agglutination.

10. At what phase does anti-P1 react at?

IGA 12 degrees C

IGG 36 degrees C

IGE 40 degrees C

IGM 24 degrees C

Anti-P1 reacts in the IGM 24 degrees C phase due to its unique temperature sensitivity.

Explanation

Anti-P1 reacts in the IGM 24 degrees C phase due to its unique temperature sensitivity.

11. At what phase do M and N ab react?

IgE RT

IgG RT

IgM RT

IgA RT

M and N ab react during the IgM RT phase, making this the correct answer.

Explanation

M and N ab react during the IgM RT phase, making this the correct answer.

12. What is required by the AABB standards for ab screening?

Confirmation of the patient's blood type using a DNA test

AHG testingCells must contain antigens to challenge 18 AgsD,C,E,c,e,M, N, S, s, K,k,Fya,Fyb,Jka,Jkb,P1,Lea,Leb

Presence of agglutination in the patient's plasma

A positive direct antiglobulin test (DAT) result

The AABB standards for ab screening specifically require cells to contain antigens to challenge a specific set of 18 Ags, as listed in the correct answer. Other options do not align with the requirements specified by AABB standards.

Explanation

The AABB standards for ab screening specifically require cells to contain antigens to challenge a specific set of 18 Ags, as listed in the correct answer. Other options do not align with the requirements specified by AABB standards.

13. What type of cells are chosen as a positive control for antigen typing?

Heterozygous cells for that ag

Non-dividing cells

Random cells from a different species

Homozygous cells for that antigen

Heterozygous cells for the antigen are chosen as a positive control because they possess both alleles for that antigen, allowing for accurate detection.

Explanation

Heterozygous cells for the antigen are chosen as a positive control because they possess both alleles for that antigen, allowing for accurate detection.

14. What is the AG frequency for M?

60%

78%

42%

93%

The correct answer of 78% represents the percentage of M in the AG sequence. The incorrect answers provide other frequency percentages to test the knowledge and understanding of the topic.

Explanation

The correct answer of 78% represents the percentage of M in the AG sequence. The incorrect answers provide other frequency percentages to test the knowledge and understanding of the topic.

15. At what phase do anti-Lewis antibodies react best?

IgE phase at 30 degrees C

IgA phase at 4 degrees C

IgM 24 degrees C

IgG phase at 37 degrees C

Anti-Lewis antibodies react best in the IgM phase at 24 degrees C due to the specific temperature and antibody class requirements for optimal interaction.

Explanation

Anti-Lewis antibodies react best in the IgM phase at 24 degrees C due to the specific temperature and antibody class requirements for optimal interaction.

16. What is the Ag freq for C?

50% Y.

30% X.

70% W

90% Z.

The Ag freq for C is 70% W, which indicates the frequency of occurrence of the element C in the context of Ag (Silver).

Explanation

The Ag freq for C is 70% W, which indicates the frequency of occurrence of the element C in the context of Ag (Silver).

17. What is the frequency of the letter 'e' in the English language?

91%

86%

98%

74%

The correct answer is 98% because the letter 'e' is the most commonly used letter in the English language and accounts for approximately 13% of all letters used.

Explanation

The correct answer is 98% because the letter 'e' is the most commonly used letter in the English language and accounts for approximately 13% of all letters used.

18. What is the Ag frequency for Lea+b+?

Common

Rare

Frequent

Occasional

In the context of blood group antigens, the term 'rare' is used to indicate that the Ag freq for Lea+b+ is not commonly found in the population.

Explanation

In the context of blood group antigens, the term 'rare' is used to indicate that the Ag freq for Lea+b+ is not commonly found in the population.

19. What is the frequency at which N appears in the given data set?

90%

72%

25%

50%

The correct answer is 72% as it represents the proportion of N in the data set. Incorrect answers are provided as distractors to test understanding of the concept.

Explanation

The correct answer is 72% as it represents the proportion of N in the data set. Incorrect answers are provided as distractors to test understanding of the concept.

20. What is the frequency of Ag for c?

80% W

40% W

60% W

100% W

The question is asking for the frequency of Ag for the element 'c'. The correct answer is 80% W, which indicates that 80% of the composition of element 'c' is Ag.

Explanation

The question is asking for the frequency of Ag for the element 'c'. The correct answer is 80% W, which indicates that 80% of the composition of element 'c' is Ag.

21. At what temperature do I agglutinate at?

IgM 24 degrees C

IgE 30 degrees C.

IgG 37 degrees C.

IgA 4 degrees C.

The correct phase for agglutination to occur is IgM at 24 degrees Celsius.

Explanation

The correct phase for agglutination to occur is IgM at 24 degrees Celsius.

22. What is the frequency of allele W for gene D?

62%

85% W

45%

78%

The correct answer is 85% because it represents the frequency of allele W for gene D in the population.

Explanation

The correct answer is 85% because it represents the frequency of allele W for gene D in the population.

23. What is the frequency of Ag for blood type a-b+?

70%

50%

90%

25%

The correct answer is 70% because individuals with blood type a-b+ have a 70% chance of having Antigen Ag present in their blood.

Explanation

The correct answer is 70% because individuals with blood type a-b+ have a 70% chance of having Antigen Ag present in their blood.

24. What is the AG frequency for P1?

91%

55%

67%

79%

The AG frequency for P1 is 79%, which indicates a high likelihood of the presence of P1 in the sample.

Explanation

The AG frequency for P1 is 79%, which indicates a high likelihood of the presence of P1 in the sample.

25. At what phase do Lutheran antibodies react?

Lu(a) - mostly IgA, Lu(b) - mostly IgG.

Lu(a) - mostly IgM, Lu(b) - mostly IgA.

Lu(a) - mostly IgG, Lu(b) - mostly IgM.

Lua - mostly IgMLub- mostly IgG

Lutheran antibodies react at Lu(a) phase with mostly IgM and Lu(b) phase with mostly IgG antibodies.

Explanation

Lutheran antibodies react at Lu(a) phase with mostly IgM and Lu(b) phase with mostly IgG antibodies.

26. What is the antigen frequency for Le a+b-?

22%

33%

10%

45%

The correct antigen frequency for Le a+b- is 22%. This specific blood group phenotype occurs in approximately 22% of the population. The incorrect answers provided do not accurately reflect the antigen frequency for Le a+b-.

Explanation

The correct antigen frequency for Le a+b- is 22%. This specific blood group phenotype occurs in approximately 22% of the population. The incorrect answers provided do not accurately reflect the antigen frequency for Le a+b-.

27. What is the AG frequency for potassium?

12%

5%

15%

9%

The correct AG frequency for potassium is 9% as indicated in the question's correct answer.

Explanation

The correct AG frequency for potassium is 9% as indicated in the question's correct answer.

28. What is the Ag freq for Le a-b-?

6%

9%

3%

12%

The Ag freq for Le a-b- is 6%. This represents the population frequency of the antigen being present in individuals who are Le a-b-.

Explanation

The Ag freq for Le a-b- is 6%. This represents the population frequency of the antigen being present in individuals who are Le a-b-.

29. What is the frequency of the element Ag in the periodic table?

30%

20%

40%

50%

The correct answer is 30%, which represents the atomic number or contribution of Silver (Ag) in the periodic table. It is essential to remember the different frequencies of elements in order to understand their properties and characteristics.

Explanation

The correct answer is 30%, which represents the atomic number or contribution of Silver (Ag) in the periodic table. It is essential to remember the different frequencies of elements in order to understand their properties and characteristics.

30. What is not required by the AABB standards for ab screening?

Autocontrol - only for pos ab screentesting, Jsa,Jsb,f,V,Cw, Kpa,Kpb,Lua,LubIS and read at 37 degrees before AHG

Direct Coombs test

Duffy antibodies

Crossmatching

The correct answer details specific requirements and exceptions for ab screening as per AABB standards, while the incorrect answers are not directly related to ab screening requirements.

Explanation

The correct answer details specific requirements and exceptions for ab screening as per AABB standards, while the incorrect answers are not directly related to ab screening requirements.