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