Antibody to Infectious Agent, Serum (Qualitative) – IgG

What This Test Measures

IgG antibodies are a type of immune protein your body produces in response to infections. This test detects their presence in your serum to determine if you’ve been exposed to specific pathogens, such as viruses or bacteria, in the past. The test is qualitative, meaning it only tells you whether antibodies are present or not, not their exact levels.

Why It’s Ordered

Doctors may order this test to diagnose or confirm past infections, screen for exposure before certain procedures (e.g., transplants), or assess immune responses in conditions like chronic infections or autoimmune diseases. It’s also used in research or screening contexts where detecting prior exposure is critical.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum (the liquid part without clots) for testing. This test does not require fasting or special preparation beyond standard blood draw procedures.

What to Expect After the Test

After your blood is drawn, you may feel slight bruising or discomfort at the site, which usually fades within a few days. Results are typically ready within a few days to a week, depending on lab processing times. Follow-up instructions from your healthcare provider will guide next steps if needed.