Antigen Antibody Titration (Serum/Plasma)

What This Test Measures

Antibody titration evaluates the concentration of antibodies in your serum or plasma. The test identifies the highest dilution of your blood where antibodies can still be detected, indicating the strength of your immune reaction to a specific antigen (e.g., virus, toxin, or foreign protein). This process helps confirm exposure, monitor immune response, or assess vaccine effectiveness.

Common Uses

Doctors may order this test to diagnose infections (e.g., viral or bacterial), evaluate vaccine responses, check for autoimmune conditions, or monitor chronic illnesses where antibodies play a role in disease progression.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The blood is then processed to separate serum (liquid part after clotting) or plasma (liquid part before clotting). The sample is sent to a lab for antibody testing using methods like immunoassay or nephelometry.

How Results Are Interpreted

Results are expressed as a dilution factor (e.g., 1:100, 1:1000) or a ratio, showing how much the sample can be diluted while still detecting antibodies. Higher titers (stronger dilutions) suggest a robust immune response, while lower titers may indicate recent exposure, low immunity, or no prior exposure.