Test ID TTF40 TTF41 (SPT24) + p40 Immunostain, Technical Component Only
Shipping Instructions
Attach the green pathology address label and the pink Immunostains Technical Only label included in the kit to the outside of the transport container.
Specimen Required
Specimen Type: Tissue
Supplies: Immunostain Technical Only Envelope (T693)
Container/Tube: Immunostains Technical Only Envelope (T693)
Preferred: 2 unstained positively charged glass slide (25 x 75 x 1mm) per test ordered; sections 4-microns thick
Acceptable: Formalin-fixed, paraffin-embedded (FFPE) tissue block
Forms
If not ordering electronically, complete, print, and send an Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.
Secondary ID
602647Useful For
Thyroid transcription factor 1 aids in the classification of carcinomas of unknown origin
p40 aids in the classification of carcinomas and lymphomas
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
IHMTO | IHC Multiplex, Tech Only | No | No |
Method Name
Immunohistochemistry
Reporting Name
TTF1 (SPT24) + p40 IHC, Tech OnlySpecimen Type
TECHONLYSpecimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
TECHONLY | Ambient (preferred) | |
Refrigerated |
Clinical Information
Thyroid transcription factor 1 (TTF1) is a nuclear protein (detected by the chromogen 3,3'-diaminobenzidine: DAB) expressed in thyroid follicular cells, type II pneumocytes, and a subset of bronchial cells. The p40 antibody recognizes the deltaNp63 isoform of p63 (detected by the chromogen fast red). The predominant localization of p40 is in the basal layer of the stratified squamous and transitional epithelia. Given the relative specificity of TTF1 for cells of thyroid or lung origin, TTF1 is often included in a panel to identify the primary site for carcinomas of unknown origin. The p40 antibody may help to distinguish squamous cell carcinomas from other non-small cell carcinomas.
Reference Values
Cautions
Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut within 6 weeks.
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysPerforming Laboratory

Test Classification
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
88344-TC