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HelpTest Code METSP MET (SP44), Semi-Quantitative Immunohistochemistry, Manual
Shipping Instructions
Attach the green "Attention Pathology" address label (T498) to the outside of the transport container before putting into the courier mailer.
Necessary Information
A pathology/diagnostic report and a brief history are required.
Specimen Required
Specimen Type: Tissue
Supplies: Pathology Packaging Kit (T554)
Submit:
Formalin-fixed, paraffin-embedded tissue block
OR
3 Unstained glass, "positively charged" slides with 4-microns formalin-fixed, paraffin-embedded tissue
Collection Instructions: Store slides at 2 to 8° C and send within 45 days.
Additional Information: One slide will be stained with hematoxylin and eosin and returned.
Useful For
Aiding in the identification of normal and neoplastic MET expressing cells
Method Name
Immunohistochemistry (IHC)
Reporting Name
MET (SP44), SemiQuant IHC, ManualSpecimen Type
SpecialSpecimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Special | Ambient (preferred) | |
| Refrigerated | ||
Reject Due To
| Decalcified paraffin embedded tissue | Reject |
| Wet/frozen tissue | Reject |
| Cytology smears | Reject |
| Noncharged slides | Reject |
| ProbeOn slides | Reject |
| Snowcoat slides | Reject |
| Nonformalin fixed tissue, including CytoLyt, SurePath, alcohol-formalin-acetic acid (AFA), 95% ethanol, PREFER and zinc formalin fixatives | Reject |
| Nonparaffin embedded tissue | Reject |
Clinical Information
MET is a cell surface receptor tyrosine kinase that regulates cellular proliferation, migration, and differentiation during development. Increased expression of MET has been shown to correlate with poor prognosis in non-small cell carcinomas of the lung and tumors of other sites. Immunohistochemistry evaluation using the MET (SP44) antibody can aid in identifying non-squamous non-small cell lung cancer patients who may be eligible for MET targeted therapies.
Reference Values
An interpretive report will be provided.
Interpretation
Results are reported as percent of tumor cells with 3+ MET protein expression.
The US Food and Drug Administration approval for treatment of non-small cell lung cancer with Telisotuzumab vedotin-tllv is for tumors with strong (3+) MET expression in at least 50% of the tumor cells.
Cautions
This test has been validated for nondecalcified paraffin-embedded tissue specimens fixed in 10% neutral-buffered formalin. Recommended fixation time is between 6 and 48 hours. This assay has not been validated on tissues subjected to the decalcification process or use of alternative fixatives for bone and bone marrow specimens or cell blocks.
Age of a cut paraffin section can affect immunoreactivity. Slides not stored at 2 to 8° C or stored at this temperature but not received for testing within 45 days of being made may have diminished antigenicity.
Method Description
Immunohistochemical staining and detection of MET (SP44) is performed in formalin-fixed, paraffin-embedded tissue sections using the VENTANA MET (SP44) RxDx Assay. The 4-micron tissue sections are deparaffinized, subjected to heat-induced antigen retrieval and peroxidase inhibitor, incubated with a rabbit monoclonal antibody, and visualized using a proprietary kit detection system. Sections are counterstained with hematoxylin and post-counterstained with bluing.(Package insert: VENTANA MET (SP44) RxDx Assay. Ventana Medical Systems, Inc.; 1018335US Rev A, 05/14/2025)
Results are examined microscopically by the consulting anatomic pathologist and interpreted using the manufacturer-provided interpretation guide.(Instruction manual: VENTANA MET (SP44) RxDx Assay Interpretation Guide for Non-Squamous Non-Small Cell Lung Cancer. Ventana Medical Systems, Inc.; 1018336US Rev A, 05/14/2025)
Day(s) Performed
Monday through Friday
Report Available
5 to 7 daysSpecimen Retention Time
Until reportedPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
88360
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| METSP | MET (SP44), SemiQuant IHC, Manual | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 623180 | Interpretation | 59465-5 |
| 623181 | Participated in the Interpretation | No LOINC Needed |
| 623182 | Report electronically signed by | 19139-5 |
| 623183 | Material Received | 81178-6 |
| 623184 | Disclaimer | 62364-5 |
| 623185 | Case Number | 80398-1 |