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Acid Fast Bacilli, technical only

Test ID: S AFB TC CPT Code: 88312 TC
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
Acid-Fast Bacilli (AFB) special stain is used to detect mycobacteria, such as Mycobacterium tuberculosis. This stain identifies organisms with high lipid content in their cell walls, rendering them resistant to decolorization by acid-alcohol solutions. In pathology, AFB stain is used as an aid in the diagnosis of mycobacterial infections. Technical component only. Pathologist read not included.

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

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.