Q.16 In ABO blood group testing, which one of the following is INCORRECT
(A) A group – agglutination with anti-A antibodies
(B) B group – agglutination with anti-B antibodies
(C) AB group – no agglutination with either anti-A or anti-B antibodies
(D) O group – no agglutination with either anti-A or anti-B antibodies
ABO blood group testing identifies antigens on red blood cells using specific antibodies, where agglutination indicates a match. Option (C) is incorrect because AB group shows agglutination with both anti-A and anti-B antibodies, not no agglutination.
Option Analysis
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(A) A group: Correct—red blood cells have A antigens, causing agglutination with anti-A antibodies but not anti-B.
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(B) B group: Correct—red blood cells have B antigens, causing agglutination with anti-B antibodies but not anti-A.
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(C) AB group: Incorrect—red blood cells have both A and B antigens, causing agglutination with both anti-A and anti-B antibodies.
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(D) O group: Correct—red blood cells lack A and B antigens, causing no agglutination with either antibody.
ABO blood group testing relies on agglutination reactions between red blood cell antigens and anti-A or anti-B antibodies, crucial for transfusions and CSIR NET life sciences exams. This method, discovered by Karl Landsteiner, determines types A, B, AB, and O based on antigen presence.
Key reactions include:
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A group RBCs agglutinate only with anti-A due to A antigens.
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B group RBCs agglutinate only with anti-B due to B antigens.
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AB group RBCs agglutinate with both anti-A and anti-B, as they express both antigens—making “no agglutination” statements incorrect.
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O group RBCs show no agglutination, lacking both antigens.
ABO Blood Group Testing Table
| Blood Group | Anti-A Reaction | Anti-B Reaction | Antigens on RBCs | Plasma Antibodies |
|---|---|---|---|---|
| A | Agglutination | None | A | Anti-B |
| B | None | Agglutination | B | Anti-A |
| AB | Agglutination | Agglutination | A and B | None |
| O | None | None | None | Anti-A and Anti-B |
