Test Catalog

Test Id : TULAB

Francisella tularensis Antibody, IgM and IgG, ELISA, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of tularemia caused by Francisella tularensis


This test should not be used as a test of cure as it is not quantitative. Patients may remain seropositive for months to years following resolution of disease.


This test detects IgM and IgG class antibodies to Francisella tularensis in serum and may be used as an aid for the diagnosis of tularemia.


Serologic testing should be performed alongside other diagnostic methods, including culture of appropriate specimens. Note: Notify the microbiology laboratory in cases of suspected F tularensis to minimize exposure risk to bench technologists.

Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test Id Reporting Name Available Separately Always Performed
TULM F. tularensis Ab, IgM ELISA, S No Yes
TULG F. tularensis Ab, IgG ELISA, S No Yes
TULI F. tularensis Interpretation No Yes

Method Name
A short description of the method used to perform the test

Enzyme-Linked Immunosorbent Assay (ELISA)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

F. tularensis Ab, IgM/IgG ELISA, S

Lists additional common names for a test, as an aid in searching



Rabbit fever

Glandular fever


Specimen Type
Describes the specimen type validated for testing


Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.6 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Heat inactivated specimen Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
Frozen 30 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of tularemia caused by Francisella tularensis


This test should not be used as a test of cure as it is not quantitative. Patients may remain seropositive for months to years following resolution of disease.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Francisella tularensis is a small, intracellular, coccobacillary gram-negative bacterium and is an obligate pathogen in animals and humans, primarily maintained in rabbits, hares, cats, ticks, and deerflies. F tularensis is found throughout North America and parts of Asia and, similar to Brucella species, is considered a potential agent of bioterrorism. Human infection with F tularensis usually occurs through inhalation of infected aerosols, ingestion of contaminated meat or water, handling of diseased or sick animals, or through the bite of an infected arthropod (eg, tick, deerflies).


Following a 3- to 5-day incubation period, the clinical manifestations of infection with F tularensis differ primarily depending on the site and route of infection. The most common form of disease is ulceroglandular (45%-80% of cases), which is associated with an arthropod (or animal) bite or another cause of skin barrier compromise. This leads to development of a painful papule that ultimately ulcerates allowing the bacterium to enter the lymphatic system. Glandular tularemia is similar in presentation to ulceroglandular disease; however, it lacks the ulceration and, more frequently, causes septicemia. Other, less frequent clinical manifestations include oculoglandular (Parinaud syndrome), oropharyngeal and gastrointestinal disease, and pneumonic or typhoidal tularemia.


Diagnostic testing options for F tularensis primarily include culture and serology. Providers suspecting tularemia should collect appropriate specimens (eg, skin lesion biopsy, lymph node aspirates) promptly and send for culture. The microbiology laboratory should be alerted to the possibility of F tularensis to ensure that appropriate safety measures are taken to protect the laboratory technologists. Growth on culture is a definitive means of making a diagnosis of tularensis. Serologic testing may be used to support a diagnosis of current or recent tularensis in patients who are IgM positive, who seroconvert to IgM, or who are IgG positive in paired sera collected 2 to 3 weeks apart.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.



Reference values apply to all ages.

Provides information to assist in interpretation of the test results

IgM result

IgG result




No antibodies to Francisella tularensis detected. Antibody response may be negative in samples collected too soon following infection/exposure. Repeat testing on a new sample in 1 to 2 weeks if clinically indicated.



IgM class antibodies to F tularensis detected, suggesting current or recent infection. Repeat testing in 1 to 2 weeks to detect seroconversion of IgG may be considered to confirm the diagnosis.





Questionable presence of IgM antibodies to F tularensis. Consider repeat testing in 1 to 2 weeks.



IgG class antibodies to F tularensis detected suggesting recent or past infection. Clinical correlation alongside presentation, exposure history and other laboratory findings required.



Questionable presence of IgM and IgG class antibodies to F tularensis. Consider repeat testing in 1 to 2 weeks.



IgM and IgG class antibodies to F tularensis detected suggesting current, recent or past infection. Cross-reactions may occur in patients with a current or prior Brucella infection. Clinical correlation alongside presentation, exposure history and other laboratory findings required.



IgG class antibodies to F tularensis detected suggesting recent or past infection. Clinical correlation alongside presentation, exposure history and other laboratory findings required.



Questionable presence of IgG antibodies to F tularensis. Consider repeat testing in 1 to 2 weeks.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

False-negative results may occur in specimens collected too soon following symptom onset, prior to the development of a detectable immune response. Repeat testing on new specimens collected 2 to 4 weeks later may be helpful.


False-positive results may occur in patients previously or currently infected with Brucella species. Other less frequent causes of cross-reactivity that have been reported include prior infection with Yersinia, Salmonella, or Legionella species.


IgM-class antibodies may be detectable as soon as 1 week after symptom onset and may remain detectable for multiple years following resolution of disease in some individuals. Therefore, an IgM-positive result may not indicate current or recent infection in some cases.


Multiple subspecies of Francisella tularensis, including F tularensis subspecies tularensis, F tularensis subspecies holarctica, and F tularensis subspecies novicida are found throughout the northern hemisphere, including in the United States. The IgM and IgG anti-F tularensis enzyme-linked immunosorbent assays used at Mayo Clinic Laboratories are based on the lipopolysaccharide (LPS) antigen of F tularensis. Although not directly tested, previous studies indicate that there are no antigenic differences between the LPS of F tularensis subspecies tularensis and the other subspecies. Therefore, these assays should not be used to differentiate between infections with the various F tularensis subspecies.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Petersen JM, Schriefer ME, Araj GE. Francisella and Brucella. In: Carroll KC, Pfaller MA, Landry ML, et al, eds. Manual of Clinical Microbiology. 12th ed. AMS Press; 2019

2. Nigrovic LE, Wingerter SL. Tularemia. Infect Dis Clin North Am. 2008;22(3):489-504. doi:10.1016/j.idc.2008.03.004

Method Description
Describes how the test is performed and provides a method-specific reference

The enzyme-linked immunosorbent assay is an immunoassay that is particularly suited to the determination of antibodies in various kinds of samples. The reaction is based on the specific interaction of antibodies with their corresponding antigen. The test strips of the microtiter plate are coated with specific antigens of the pathogen of interest. If antibodies in the sample are present, they bind to the fixed antigen. A secondary antibody, which has been conjugated with the enzyme alkaline phosphatase detects and binds to the immune complex. The colorless substrate p-nitrophenylphosphate is then converted into the colored product p-nitrophenol. The signal intensity of this reaction product is proportional to the concentration of the analyte in the sample and is measured photometrically. (Package insert: Francisella tularensis IgG/IgM ELISA, Immuno-Biological Laboratories Inc; V 142.6)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday, Thursday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

86668 x 2

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
TULAB F. tularensis Ab, IgM/IgG ELISA, S 93715-1
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
TULM F. tularensis Ab, IgM ELISA, S 93716-9
TULG F. tularensis Ab, IgG ELISA, S 93717-7
TULI F. tularensis Interpretation 93718-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports