Francisella tularensis Antibodies, IgG and IgM, ELISA Serum

Tularemia Antibody (Francisella tularensis), Rabbit fever

Test Codes

Order Reference Lab Miscellaneous Send Out: EPIC: LAB848, Beaker: Ref. Lab. Misc., Quest: 12707

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and keep at room temperature (20-26°C or 68-78.8°F).

Preparation for Courier Transport

Transport: 0.6 mL serum, at room temperature (20-26°C or 68-78.8°F). (Minimum: 0.5 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and keep at room temperature (20-26°C or 68-78.8°F).

Transport: 0.6 mL serum, at room temperature (20-26°C or 68-78.8°F). (Minimum: 0.5 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Tuesday, Thursday, Saturday.
Results available in 3-5 days.

Reference Range

F tularensis Ab (IgG):   Negative

F tularensis Ab (IgM):  Negative

Test Methodology

Enzyme Linked Immunosorbent Assay (ELISA)

Clinical Utility

Francisella tularensis Antibodies (IgG, IgM) – This immunoassay is for the qualitative detection of antibodies (IgG, IgM) against Francisella tularensis, the causative agent of Tularemia disease. Antibodies can be detected starting 2-3 weeks after the onset of symptoms. Paired sera 2-3 weeks apart to observe seroconversion is recommended to confirm infection in patients with high clinical suspicion.

This assay is intended for patients with signs and symptoms consistent with acute Tularemia and not useful for patients with resolved infection. Tularemia can cause a wide spectrum of symptoms depending on exposure. People rarely can be infected through tick and deer fly bites, contact with infected animals, drinking contaminated water, or inhalation.

Antibodies against other bacteria, including Brucella, can cross-react with assays targeting Francisella. Therefore, positive serologic results should be interpreted in the context of clinical illness and exposure consistent with Tularemia infection. Antibodies can persist for years and IgM in a single sample is not a reliable indicator of recent infection. Positive IgG and IgM results can represent current, recent, or past infection since they can be detected for several years post infection. A negative result can occur early during acute infection, before the development of antibodies.

CPT Codes

86668 x 2

Contacts

Last Updated

8/27/2026