Laboratory Services

Toxoplasma gondii Antibody, IgM, Serum

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Updated Test Information:

Test Description
Toxoplasma gondii Antibody, IgM, Serum

T. gondii; Toxoplasma gondii; Toxoplasma IgM Antibody Assay; Toxoplasmosis; Torch; TorC

Test ID
General Information

Useful for detection of recent infection with Toxoplasma gondii

Specimen Type


Specimen Requirements

  • Preferred: Serum Gel (SST)

  • Acceptable: Red Top


  • Refrigerated (preferred): 14 days

  • Frozen: 14 days

Unacceptable Specimen Conditions

  • Gross hemolysis

  • Gross lipemia

  • Heat-inactivated specimen


  • Diagnosis of recent infection by Toxoplasma gondii can only be established on the basis of a combination of clinical and serological data

  • The result of a single serum sample does not constitute sufficient proof for diagnosis of recent infection

  • If a serum sample was collected too soon after infection, IgM antibodies to Toxoplasma gondii may be absent. If this is suspected, a second serum sample should be collected 2 to 3 weeks later and the test repeated

  • Results should be interpreted with caution in HIV-positive patients, patients receiving immunosuppressive therapy, or individuals with other disorders leading to immunosuppression

  • Heterophile antibodies in the patient samples may interfere with the assay performance

  • The performance of the assay has not been established for cord blood testing

  • As with any low prevalence analyte, there is the increased possibility that a positive result may actually be false, reducing the assay's positive predictive value. Per the Public Health Advisory (7/25/1997), the FDA suggests that sera found to be positive for Toxoplasma gondii IgM antibodies should be submitted to a Toxoplasma reference laboratory


Multiplex Flow Immunoassay (MFI)

Estimated TAT

1-3 days

Testing Schedule



14 days

CPT Code(s)


Additional Information
Minimum Sample Volume

0.8 mL

Reference Range


Performing Lab


LOINC Code(s)