tb quantiferon gold
ImmunologyBlood sampleResults 3-5 daysNo fasting
TB Quantiferon Gold
A blood test that checks for tuberculosis infection by measuring the immune response to TB proteins. A convenient alternative to the skin test, with no return visit needed.
Sample
Blood
Results
3-5 days
Fasting
Not required
Follow-up
Optional add-on
What this test detects
Interferon-gamma response to TB antigens
Interferon-gamma release assay
Qualitative · Positive/Negative/Indeterminate
When to get this test
Latent TB detection
Identifies TB infection even when there are no symptoms.
TB contact screening
Useful for people exposed to someone with tuberculosis.
Prior BCG vaccination
Less affected by past BCG vaccination than the skin test.
How to prepare
01
No special preparation needed.
Common questions
How is this different from the skin test?
It is a single blood draw with no return visit, and it is generally not affected by previous BCG vaccination.
Does a positive result mean active TB?
It indicates TB infection but does not distinguish latent from active disease, so additional evaluation may be needed.