Special Stain, Congo Red
Also known as: CONGO R SS
Use
The Congo Red special stain is used in histopathology to detect amyloid deposits in tissue specimens. Amyloid characteristically exhibits apple‑green birefringence under polarized light after staining, aiding in diagnostic evaluation of amyloidosis and related conditions.
Special Instructions
This stain is performed as a stain‑and‑return (technical) service only. Ordering is recommended via electronic request using the ARUP Anatomic Pathology Test Request Form (#32960). Transport of formalin‑fixed, paraffin‑embedded tissue blocks or at least two unstained positively charged slides (8 to 10 microns thick; minimum one slide) using ARUP supply #47808 tissue transport kit is required. Protect specimens from excessive heat and ship in cooled containers during summer months.
Limitations
Frozen specimens are unacceptable. Specimens that are depleted or do not contain representative tissue are unacceptable. Slides and blocks must be formalin‑fixed and paraffin‑embedded (cells must be in cell blocks). Interpretation is technical only; no clinical interpretation is provided.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 10782-1
Result Turnaround Time
1-5 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (Fixed (Non-FFPE))
Volume
Not provided
Minimum Volume
Min: 1 slide
Container
Tissue transport kit (ARUP supply #47808)
Collection Instructions
Transport tissue block or 2 unstained (8‑ to 10‑micron thick), positively charged slides.
Causes for Rejection
Nonrepresentative tissue type; depleted specimens; frozen specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Indefinitely (Ambient) |
| Refrigerated | Indefinitely |
| Frozen | Unacceptable |