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Coombs

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Coombs, Coombs Reagent

  • Coombs Reagent
  1. Anti-Human Globulin Antibody
  2. Binds to human IgG Antibody and C3 Complement
  3. Produced in rabbits by Immunization
  • Direct Coombs
  1. Question
    1. Is IgG or complement bound to Red Blood Cell?
  2. Technique
    1. Start with patient's Red Blood Cells
    2. Add Anti-human globulin antibodies (Coombs Reagent)
  3. Direct Coombs Positive
    1. Agglutination indicates Antibody coated RBCs
  4. Example of use
    1. Are maternal antibodies bound to fetal RBCs?
  • Indirect Coombs
  1. Question
    1. Is Antibody against Red Blood Cell present in serum?
  2. Technique
    1. Start with patient's serum
    2. Add Anti-human globulin antibodies (Coombs Reagent)
    3. Add Indicator Red Blood Cells with known antigens
  3. Indirect Coombs Positive
    1. Agglutination indicates Antibody to RBC in serum
    2. Antibody titer can be obtained by serial dilution
  4. Example of use
    1. Are antibodies to fetal RBC present in maternal serum