Detects the genetic material (DNA/RNA) of Mycobacterium tuberculosis using PCR.
Directly confirms an active infection, often earlier than antibody tests can. Used in the diagnosis of tuberculosis (TB).
Cough for more than 2 weeks, breathlessness, wheezing, fever with chest symptoms, or TB exposure.
No fasting needed.
This article is for general information and education only. It is not medical advice, does not create a doctor–patient relationship, and is not a substitute for consultation with a qualified doctor who has assessed your individual situation. Never delay seeking medical advice because of something you have read here.
In a medical emergency, call 112, or 108 for an ambulance where that service operates, or go to your nearest emergency department. If you are in mental health distress, Tele-MANAS is free and available 24×7 on 14416.
Read our Editorial Policy and Medical Review Process.
PCR detects the organism itself, so it is very useful early in infection; antibody tests show the body's response and are useful later.
No fasting is needed. You can eat and drink normally unless your doctor has advised otherwise.
Sputum or other sample (fluid, tissue, pus) as advised; culture-based tests may use a positive culture.
Usually within 3–4 days after the sample reaches the lab. You will receive the report online.