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Department of Health Services

Public Health Regional Laboratory

Quantiferon Gold Plus

This test is a blood-based interferon-gamma release assay (IGRA) used as an aid in the diagnosis of Mycobacterium tuberculosis infection. It is an immune response-based, indirect test for M tuberculosis infection (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. Additional testing is needed to determine if a person who has tested positive has latent tuberculosis (TB) infection or TB disease.

Portal Ordering Code

QFT

CPT Code(s)

86480

Fee Schedule

Storage and Transport Criteria
Specimen Storage Specimen Transport
Acceptable Specimens
Minimum Volume
Frozen Range
-70°C - 0°C
Refrigerated Range
0.1°C - 8°C
Room Temperature Range
8.1°C - 30°C
Stability at
4°C - 25°C
Li-Heparin plasma, non-incubated Li-Heparin plasma-6 mls Reject Acceptable at 2°C – 8°C up to 48 hours Acceptable at 17°C – 25°C up to 12 hours 8 hours
Includes

N/A

Methodology

ELISA

Assay Category

FDA Approved

Reference Range

See laboratory report

Alternative Names
  • QFT Gold Plus
  • IGRA
  • QFT Plus
  • TB Gold
  • QFT TB
Preferred Specimen(s)

Li-Heparin plasma, 1 tube, non-incubated

Alternative Specimen(s)

Quantiferon-TB Gold Plus Blood Collection Tubes (1 mL per tube)

Minimum Volume

Li-Heparin plasma-6 mls

Special Instructions

Collect a minimum of 6 mL of blood by venipuncture into a lithium heparin (green-top) tube. Gently mix by inverting the tube several times to dissolve the heparin.
Refrigerate at 2-8° C. Note that when using QuantiFERON®-TB Gold Plus, blood samples must be processed within 16 to 48 hours after collection while white blood cells are still viable.

Reject Criteria
  • Inadequately labeled specimens
  • Leaking specimens
  • QNS (quantities not sufficient)
  • Specimens not meeting the Storage & Transport criteria upon receipt at laboratory
Setup Schedule

Testing done once a week.

Turn around time (TAT)

7 business days from arrival at the lab