Grocott's Methenamine Silver Stain
Use
Grocott methenamine silver (GMS) stain is used to detect fungi, including Pneumocystis jirovecii, the causative agent of Pneumocystis pneumonia. This stain imparts a black color to fungal cell walls, facilitating their identification under a microscope. Additionally, GMS can stain other organisms and non-organic substances, such as melanin, mucins, and glycogen, providing valuable diagnostic information.
Special Instructions
Fresh Tissue: Specimens may be fixed in formalin for 6-72 hours by collection sites, then transferred to 70% ethanol and stored at 2-8°C for longer term storage if needed. This is NOT preferred. Samples should be tested 3 months after placing in ethanol. Unstained slides: Positively charged glass slides required to prevent background staining and prevent tissue loss. Slides should be left unbaked.
Limitations
The test is limited to detecting the presence of fungi and some non-organic substances. It may not detect all types of fungi with equal sensitivity. Results can be affected by the quality of the specimen and fixation process. Specimens fixed with non-recommended fixatives will be rejected.
Methodology
Other (Anatomic Pathology)
Biomarkers
Result Turnaround Time
2 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (Fixed (Non-FFPE))
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Fixative should be at a 20:1 fixative to tissue ratio, 10% neutral buffered formalin (NBF) for 6-72 hours (48-72 hours PREFERRED).
Storage Instructions
Store at 15°C to 25°C. For longer-term storage, specimens may be transferred to 70% ethanol and stored at 2-8°C after fixation.
Causes for Rejection
Specimens must be fixed in 10% NBF or B plus. All other fixatives will be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 Hours |