Cytomegalovirus (CMV) IgG Antibody, Serum or Plasma

The CMV IgG test is a blood test that measures IgG antibodies to cytomegalovirus (CMV), a common virus. A positive result shows that your immune system has encountered CMV at some point in your life, since these antibodies usually remain in your blood permanently after an infection clears.

The CMV IgG antibody test detects specific proteins (antibodies) your immune system produces in response to past infection by the cytomegalovirus. These antibodies remain in your blood for years after recovery, helping doctors assess exposure history rather than active infection.

Your doctor may order this test if you have symptoms that could be related to CMV, if you are pregnant or planning a pregnancy, if you are about to receive an organ transplant or donated blood, or if you have a weakened immune system and need monitoring for past or recent CMV exposure.

Your healthcare provider may order this test if you have a weakened immune system (e.g., due to HIV, chemotherapy, or organ transplant), are pregnant, or have symptoms like fever, fatigue, or organ damage that could suggest CMV infection.

Results are usually available within one to three business days after your blood sample reaches the laboratory. Timing can vary depending on the lab and your healthcare provider's office, so ask your care team when and how you will be contacted with your results.

Results are typically available within 1–3 business days. A positive result means you likely had CMV at some point, while a negative result suggests no detectable antibodies, indicating either no prior exposure or recent infection.

Very little preparation is needed. No fasting is required for this test. A healthcare professional will clean your skin, draw a small sample of blood from a vein in your arm, and apply a bandage. The procedure takes only a few minutes, and you can return to your normal activities right away.

No special preparation is needed. You may provide either serum (blood plasma after clotting) or plasma (blood plasma without clotting), depending on lab protocols. Avoid alcohol or strenuous activity 24 hours before testing if instructed.