Methylthioadenosine Phosphorylase (MTAP), Diagnostic, Immunostain, Tech Only
Use
The Methylthioadenosine Phosphorylase (MTAP) test is useful for the qualitative detection of MTAP in a diagnostic setting. It aids in the diagnosis of mesothelioma by providing a reliable marker for malignancy in mesothelial proliferations, as the loss of expression of the MTAP protein is indicative of such conditions. MTAP is related to chromosome 9p21.3 and is involved in purine metabolism. It plays a role in the salvage of adenosine and methionine and is expressed in mesothelial cells. Loss of MTAP expression may also occur in a subset of carcinomas.
Special Instructions
This test performs only the technical component of the immunostain without providing pathologist interpretation. It should not be ordered with a PATHC/Pathology Consultation, as the technical component stains will be canceled if ordered in conjunction with PATHC. Attach the green 'Attention Pathology' address label and the pink Immunostain Technical Only label to the transport container. Clients must order electronically to have access to digital images of the stains.
Limitations
The test does not include pathologist interpretation; only technical performance of the stain is provided. Age of a cut paraffin section can affect immunoreactivity and stability thresholds vary widely. Best practice is to have paraffin sections cut within 6 weeks. The assay has not been validated on tissues subjected to decalcification or non-standard fixation processes such as for bone or bone marrow specimens. Environmental factors can affect slide charge, influencing staining. It's recommended to minimize storage time, and exposure to high humidity and heat for positively charged slides.
FDA ApprovedNew York Approved
Methodology
Immunoassay (IHC)
Biomarkers
LOINC Codes
- Order only;no result
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Container
Immunostain Technical Only Envelope
Collection Instructions
Submit formalin-fixed, paraffin-embedded tissue block or 2 unstained, positively charged glass slides (25- x 75- x 1-mm) per test ordered; sections 4-microns thick.
Storage Instructions
Attach the appropriate labels to the transport container. Minimize exposure to high humidity and heat.
Causes for Rejection
Wet/frozen tissue, Cytology smears, Nonformalin fixed tissue, Nonparaffin embedded tissue, Noncharged slides, ProbeOn slides, Snowcoat slides
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Ambient (preferred) |