The Indirect Antiglobulin Test (IAT), also known as the indirect Coombs test, is used to detect **antibodies in a patient's serum** that can react with specific antigens on red blood cells (RBCs). **Principle**: 1) **Incubation Phase**: The patient's serum is incubated with reagent RBCs (or donor RBCs in crossmatch) that possess known antigens. If the serum contains antibodies specific to those antigens, the antibodies will bind to the RBCs, coating them. This step occurs at 37°C to allow optimal binding of clinically significant IgG antibodies. 2) **Washing Phase**: The RBCs are thoroughly washed with saline to remove any unbound serum proteins, including immunoglobulins that are not specifically attached. 3) **Addition of Antiglobulin Reagent**: Anti-human globulin (AHG) reagent (containing antibodies against human IgG and/or complement components like C3d) is added. 4) **Agglutination**: If the RBCs were coated with antibody (or complement) during incubation, the AHG will bridge between the antibody molecules on adjacent RBCs, causing visible **agglutination** (a positive result). If no antibody was bound, the AHG has nothing to bind to, and no agglutination occurs (negative result). The IAT is fundamental for antibody screening, identification, and crossmatching.

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Zambia

• loveness Phiri – 1084 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies