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Lab test

Toxoplasma Antibody (IgG) Test

This test measures the level of IgG antibodies against Toxoplasma gondii in a blood sample. IgG antibodies reflect past or ongoing exposure to the parasite that causes toxoplasmosis, and titers can remain elevated for years after exposure.

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About this test

Toxoplasma gondii is a parasite, and toxoplasmosis is the infection it causes. This test measures the titer, or level, of IgG antibodies against the parasite in serum using an immunoassay method.

In the context of pregnancy, rising IgG titers measured in a newborn after birth, when a placental leak is not present, can be consistent with the newborn's own infection with Toxoplasma gondii rather than antibodies carried over from the mother. This is one reason a clinician may follow IgG levels over time rather than reading a single value in isolation.

Test details

CollectionQuest patient service center

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Additional details

What this test looks at

The test reports one value: the IgG antibody titer against Toxoplasma gondii in serum, measured by immunoassay. It is a different marker from IgA or IgM antibody tests for the same parasite, which reflect a different stage or timing of exposure.

This test isn't part of the Celio Health store at the moment, so it can't be ordered or requested here. The test menu lists everything that can.

Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.

Frequently asked questions

What does this test measure?

It measures the titer of IgG antibodies against Toxoplasma gondii in a serum sample, using an immunoassay method.

How is the sample collected?

The test uses a serum sample from a routine blood draw.

Do I need to prepare for this test?

No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.

What does a raised IgG titer mean?

It reflects exposure to Toxoplasma gondii at some point, since IgG titers can stay elevated for years after exposure. A clinician reads the level together with history and, when relevant, other antibody results rather than on its own.

Is this the same as the IgA or IgM Toxoplasma antibody test?

No. This test measures IgG antibodies specifically. IgA and IgM antibody tests for Toxoplasma gondii are separate products that reflect different aspects of exposure timing.

Last updated 2026-09-18 · How we write about lab testing

Educational content

This page is for general educational purposes only. It is not medical advice, and it is not a substitute for consultation with a qualified healthcare professional. Laboratory results should always be interpreted by a licensed clinician who knows your health history. If you have questions about your health or your results, talk with your doctor. If you think you may be experiencing a medical emergency, call 911.