Keratin 20 (KRT20) Immunostain, Technical Component Only
Use
The Keratin 20 (KRT20) immunostain is primarily used in assessing carcinomas of unknown primary origin. It stains the cytoplasm of epithelial cells with a granular or filamentous pattern, and expression is mainly restricted to the epithelium of the lower gastrointestinal tract, urothelium, and Merkel-cells. It is commonly positive in colon carcinomas and, together with cytokeratin 7, aids in determining the primary site of malignancy.
Special Instructions
This test provides only the technical performance of the immunohistochemical stain, and it excludes pathologist interpretation. If interpretation is needed, a separate pathology consultation should be ordered. The technical component stains should not be ordered together with a Pathology Consultation as they will be canceled. Use the provided green pathology address label and pink Immunostain Technical Only label when shipping specimens.
Limitations
Paraffin sections older than 6 weeks can impact immunoreactivity due to antigen degradation. Environmental factors can affect the charge of glass slides, leading to inconsistent staining. Ensure slides are properly stored to minimize exposure to humidity and heat. Nonformalin fixed, non-paraffin embedded tissues, or improperly charged slides are not accepted for this test.
New 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
Preferred specimens include formalin-fixed, paraffin-embedded tissue block or 2 unstained, positively charged glass slides per test ordered; sections should be 4-microns thick.
Storage Instructions
Ambient temperature is preferred. Refrigerated conditions are also acceptable.
Causes for Rejection
Wet/frozen tissue, cytology smears, nonformalin fixed tissue, nonparaffin embedded tissue, noncharged slides, ProbeOn slides, and Snowcoat slides.