Skip to Main Content

View Related Pages

QuantiFERON-TB Gold

Principle

Tuberculosis (TB) remains a major global infectious disease caused by Mycobacterium tuberculosis, which can result in latent infection or active pulmonary and extrapulmonary disease. Early identification of latent TB infection (LTBI) is critic

Specimen Requirements

Specimen

Whole blood (lithium-heparin preferred prior to transfer)

Collection

Collect minimum 5 mL blood by venipuncture

Processing

Centrifuge 2000–3000 RCF for 15 minutes to separate plasma

Storage and Transport

  • 2–8°C: up to 28 days
  • ≤ −20°C: for extended storage (if required)

More Information

  • Tube System: Transfer 1 mL blood into each QFT tube:
    • Nil (gray)
    • TB1 (green)
    • TB2 (yellow)
    • Mitogen (purple)
  • Mixing: Invert each tube 10 times immedi

Method

Interferon Gamma Release Assay (IGRA) with ELISA-based IFN-γ quantification

Results

Results are based on TB antigen response relative to Nil control and Mitogen response.

Negative:
No significant IFN-γ response to TB1 or TB2 antigens.
Findings suggest no evidence of M. tuberculosis infecti

Turnaround Time

2–3 days (depending on batching and ELISA schedule)

References

  1. Pai M et al. Interferon-gamma release assays for diagnosis of latent tuberculosis infection. Lancet Infect Dis.
  2. Lalvani A. Diagnosing tuberculosis infection in the 21st century. Lancet Infect Dis.
  3. QuantiFERO