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Thyroid Transcription Factor-1 (TTF-1) Antigen, Tissue — Qualitative Immunohistochemical Stain

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

A qualitative test that detects TTF-1 protein in a tissue sample to help identify the likely source of certain abnormal cells.

Quick summary

["TTF-1 staining can help pathologists determine whether abnormal cells may have come from lung or thyroid tissue."]

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

Key facts at a glance

LOINC
40564-7
Short code
TTF1 Ag Tiss Ql ImStn
Synonyms
TTF1 Ag Tiss Ql ImStn
Category
thyroid
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-stain
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 is this test?

This is an immunohistochemical test performed on tissue. It uses antibodies to detect the TTF-1 protein, also called thyroid transcription factor-1, which is found in the nuclei of certain cells.

Why might I need this test?

A pathologist may order this test when identifying the origin of cancer cells found in a biopsy or surgical specimen. TTF-1 can provide evidence of lung or thyroid origin, but the result is interpreted with the tissue appearance and other laboratory findings.

How is the test performed?

Tissue obtained through a biopsy or surgery is processed and exposed to TTF-1 antibodies. The stained cells are examined under a microscope, and the result is reported as positive or negative for TTF-1 expression.

How do I prepare for the test?

No special preparation is needed for the stain itself. If a biopsy is required, follow the instructions provided by your healthcare professional about fasting, medications, and procedure-specific precautions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

TTF-1 expression can support a diagnosis of certain lung or thyroid cancers, especially when the tissue has an appearance consistent with those conditions. A negative result does not by itself exclude a particular cancer or prove another tissue source. Interpretation depends on the specimen, staining quality, other biomarkers, and the pathologist's overall findings.

Short name

TTF-1 tissue immunostain

Frequently asked questions

Is the TTF-1 test the same as a thyroid blood test?
No. This test examines TTF-1 protein in tissue rather than measuring thyroid hormones or antibodies in blood.
Does a positive TTF-1 result diagnose cancer?
No. It is one piece of information that can support or narrow a diagnosis but must be interpreted with other pathology findings.
What happens if the TTF-1 result is negative?
A negative result means that detectable TTF-1 expression was not found in the tested tissue. The pathologist may use additional stains and clinical information to determine the cause.
  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