Days Set Up
Monday, Thursday
Analytic Time

2 - 7 days

MiChart Code
Thyroid Stimulating Immunoglobulin
Soft Order Code

Test Updated:


LATS (Long Acting Thyroid Stimulator)
Long Acting Thyroid Stimulator (LATS)

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Test Overview

Test Methodology

Chemiluminescent Immunoassay

Test Usage

Diagnosis of hyperthyroidism; diagnosis of patients with normal routine thyroid tests but in whom progessive exophthalemia and/or Grave's disease is still suspected.

Reference Range

<0.55 IU/L
Thyroid Stimulating Immunoglobulin is measured by the Siemens Immulite 2000 Chemiluminescent Immunoassay method. The cutoff value of 0.55 IU/L was determined from a ROC curve analysis and has consistently shown a sensitivity of >98% and specificity of >99% for the diagnosis of Graves’ Disease.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Offsite

Collect blood in an SST tube. Centrifuge, aliquot serum into plastic vial and refrigerate up to 7 days or freeze for longer storage.

Red Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.3 mL serum

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.