TB Gold Blood Test in California

The TB Gold Blood Test is a blood test used to check whether you have been infected with the bacteria that cause tuberculosis (TB). It is often ordered when a person has symptoms of TB, has been in close contact with someone with TB, or needs screening for work, school, or travel.

What it measures

TB-specific antigens — Proteins from the TB bacteria that trigger a response if you have been infected.
Interferon-gamma (IFN-γ) — A substance made by your immune cells when they recognize TB antigens.
Mitogen control — A positive control to show your immune cells are working properly.
Nil control — A negative control to check for background noise in the test.

Who it is for

This test is typically ordered by primary care doctors, infectious disease specialists, or occupational health providers. It is commonly used for people who have symptoms of TB, have been exposed to TB, or need screening before starting certain jobs or treatments.

Preparation

No fasting or special preparation is needed for this test. You can eat and drink normally before your blood draw.

Results and what they mean

Results are usually reported as positive, negative, or indeterminate, along with the measured levels of interferon-gamma. A positive result means you have been infected with TB bacteria, but it does not tell whether you have active TB disease or a latent infection. Only a clinician can interpret your results in the context of your health history and other tests. This information is not medical advice.

Requesting the TB Gold Blood Test in California

Order online, choose a certified collection site in California, and review results through a secure portal. No referral is required, and orders are processed confidentially. Because the region is uneven, coastal metros, inland towns, and rural counties with very different access to testing — worth planning around when you book.

Frequently asked questions

Does a positive result mean I have active TB?

No. A positive result only shows that you have been infected with TB bacteria. It cannot distinguish between latent TB infection (where you are not sick and not contagious) and active TB disease. Your doctor will do further tests to find out.

How is this test different from a TB skin test?

The TB Gold blood test requires a single blood draw and does not need a follow-up visit. A TB skin test requires two visits and can be affected by prior BCG vaccination, while the blood test is not.

Can I get TB from this test?

No. The test uses synthetic proteins from the TB bacteria, not live bacteria, so there is no risk of getting TB from the test.

What if my result is indeterminate?

An indeterminate result means the test could not give a clear answer, often because your immune cells did not respond as expected. Your doctor may repeat the test or order other tests.

TB Gold Blood Test by city in California

All testing in California → Full TB Gold Blood Test guide →