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Tuberculosis Antibody Screening (Serum/Plasma) – Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

This blood test detects antibodies your immune system makes in response to tuberculosis (TB) bacteria. It helps screen for past or current exposure.

Quick summary

["A TB antibody screen checks for signs of TB infection, often used in routine or high-risk screening."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
33641-2
Short code
LPT Tuberc Bld-aCnc
Synonyms
LPT Tuberc Bld-aCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85610
SNOMED
396252006
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What This Test Measures

The test measures the presence and level of antibodies (proteins) your body produces when it encounters TB bacteria. These antibodies can appear after infection, even if symptoms aren’t active. The method used may involve immunoassay techniques to detect these antibodies in your serum or plasma.

How the Test Works

Your blood sample is tested to identify specific antibodies linked to TB. If antibodies are found, it suggests your immune system has recognized TB bacteria, possibly from past exposure or infection. This doesn’t confirm active TB but helps determine if further testing is needed.

When You Might Need This Test

This screening is commonly used in high-risk groups (e.g., travelers to TB-endemic regions, healthcare workers, or individuals with weakened immune systems). It may also be part of routine check-ups in areas with higher TB prevalence.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted to draw blood from a vein in your arm. The process usually takes a few minutes, and you can resume normal activities afterward.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: whole-blood

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Tuberculosis Antibody Screen

Frequently asked questions

Why did my doctor order this test?
Your doctor may recommend this screening if you’re at risk for TB exposure, such as traveling to certain regions, having a weakened immune system, or working in a high-exposure setting. It helps identify potential infection early for further evaluation.
What does a positive result mean?
A positive result suggests your body has detected TB bacteria, but it doesn’t confirm active TB. You may need additional tests (like a TB skin test or chest imaging) to determine if you have an active infection or just past exposure.
Can I get TB from a positive antibody test result?
No, a positive antibody test means your immune system has responded to TB bacteria, but it doesn’t indicate active infection or contagiousness. Active TB requires specific symptoms and further medical evaluation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy