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Grocott's Methenamine Silver Stain

Test ID: S GMS CPT Code: 88312
Expected Turnaround Time
2 days
Stated turn-around-times (TATs) are for clinical use only and subject to change based on biopharma protocol requirements. Final TATs will be specified in the biopharma study contract.
Clinical Information
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.

Specimen Requirements

Specimen Requirements
  • Fresh Tissue: Fixative should be at a 20:1 fixative to tissue ratio, 10% neutral buffered formalin (NBF) for 6-72 hours (48-72 hours PREFERRED)
  • Formalin-fixed Paraffin Embedded Tissue (FFPE blocks): FFPE Block, Formalin Fixed
  • Unstained slides: 2 slides (3-5 μM) per stain (min 1 slide per stain), Formalin Fixed
Specimen Stability
  • Formalin-fixed, Paraffin-Embedded (FFPE) tissues: Indefinite
  • Fresh Tissue tissues: ≤ 72 Hours
  • Unstained slides: Indefinite
Storage Requirements

15°C to 25°C

Shipping Conditions
Ambient
Shipping Recommendations
  • Fresh Tissue: AMBIENT
  • Formalin-fixed Paraffin Embedded Tissue (FFPE blocks) and unstained slides: AMBIENT, Use a refrigerated (NOT FROZEN) gel pack in the shipment to protect from extreme temperatures. Separate gel pack from specimen.
  • Specimens may be transferred to 70% alcohol for transportation purposes after fixation in 10% NBF or B plus.
Specimen Rejection Criteria

Specimens must be fixed in 10% NBF or B plus. All other fixatives will be rejected. 

Test Details

Synonyms

Grocott–Gömöri's

Test Method
Anatomic Pathology
Methodology Category
Anatomic Pathology
Regulatory Status
IVD, CE-marked
Special Considerations
  • 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.