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Toxoplasma gondii IgG Antibody, Serum

Published: August 9, 2026Updated: August 16, 2026

This test checks for antibodies to the parasite *Toxoplasma gondii*, which can indicate past or current exposure to toxoplasmosis.

Quick summary

["Past exposure to toxoplasmosis may be detected by this blood test."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
25300-5
Short code
T gondii IgG 1:2 Ser-Rto
Synonyms
T gondii IgG 1:2 Ser-Rto
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does This Test Measure?

The test measures IgG antibodies in your blood. IgG antibodies are a type of immune protein that your body produces in response to an infection. If you have had toxoplasmosis in the past, your body will have these antibodies. This test does not detect active infection but helps determine if you’ve been exposed to the parasite.

Why Might This Test Be Ordered?

Your healthcare provider may order this test if you have symptoms like fever, fatigue, or muscle pain that could suggest past exposure to toxoplasmosis. It may also be used in pregnant women to assess risk of congenital toxoplasmosis or in people with weakened immune systems to monitor exposure.

What Does a Positive Result Mean?

A positive result means your body has produced IgG antibodies against *Toxoplasma gondii*, suggesting you’ve likely been exposed to the parasite at some point. This does not confirm an active infection but indicates immunity or past infection.

What Does a Negative Result Mean?

A negative result means your body did not detect IgG antibodies to the parasite, which could mean you’ve never been exposed or the test was taken too early after exposure. Follow-up testing may be needed if you suspect exposure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

IgG antibodies to *Toxoplasma gondii* are important for understanding past exposure, especially in high-risk groups like pregnant women or those with immune conditions. While IgG alone does not diagnose active infection, it helps guide further testing or preventive measures if needed.

Short name

IgG Antibody to Toxoplasma

Frequently asked questions

How is this test performed?
The test involves drawing blood from a vein in your arm. A small amount of blood is collected and sent to a lab for analysis.
What preparation is needed?
No special preparation is required for this test. You may eat and drink normally before your appointment.
Can this test detect active infection?
No, this test only detects IgG antibodies, which indicate past exposure. To check for active infection, your provider may order additional tests, such as IgM antibodies or other diagnostic evaluations.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy