Understanding This Medical Test: What It Is, How It Is Performed, and Why It Matters for Your Health and Care
This test detects genetic mutations in the embB gene that may cause bacterial resistance to certain antibiotics.
{"Detects genetic changes (mutations) in bacteria that may cause antibiotic resistance","Helps doctors choose the right antibiotics for treatment","Uses molecular methods to analyze bacterial DNA from patient sample","Results help guide personalized treatment plans","Sample is collected as serum (blood)"}
Key facts at a glance
- LOINC
- 94058-5
- Short code
- EMBB
- Synonyms
- Bacterial embB drug res mut Islt/Spm
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container; appropriate mycobacterial transport medium if applicable
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- molgen
- CPT
- 87556
- SNOMED
- 1003571000124102
- Specimen volume
- 1-10 mL depending on specimen type (sputum, BAL, tissue, CSF); minimum 1 mL for fluid specimens
- Stability
- Refrigerated (2-8°C) for up to 7 days; frozen at -70°C or below for longer storage. Transport to laboratory promptly to maintain nucleic acid integrity.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–168 hours
- Order
- routine
What is this test, and what does it check for?
The embB gene drug resistance mutation test is a molecular diagnostic test that detects specific genetic mutations in bacteria. The embB gene is particularly important in Mycobacterium tuberculosis (the bacteria that causes tuberculosis). When this gene mutates, it may make the bacteria resistant to ethambutol, a common antibiotic used to treat tuberculosis. This test analyzes the bacterial DNA from your sample to identify whether these resistance-causing mutations are present.
How is this test performed, and what can I expect during the procedure?
A blood sample will be collected from you by a healthcare professional. The sample is then sent to a laboratory where molecular techniques (such as PCR or gene sequencing) are used to detect mutations in the embB gene. These methods can identify specific genetic changes that are associated with antibiotic resistance.
Why is this test important, and how can the results help guide my care?
This test is crucial for effective treatment planning. If the test detects resistance mutations, your doctor can avoid prescribing antibiotics that won't work and instead choose alternative medications that are more likely to be effective. This helps ensure better treatment outcomes and prevents the spread of drug-resistant bacteria.
Reference range
Reportable as 'Mutation Detected' or 'No Mutation Detected' for embB gene drug resistance. Interpretation provided with detected codon positions (commonly embB306, embB406, embB497). Specific mutations are reported individually when present.N/A
No special patient preparation required. Specimen should be collected prior to initiation of anti-tuberculosis therapy when possible to avoid false-negative results due to non-viable organisms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The presence of embB gene mutations indicates potential resistance to ethambutol, an important first-line antibiotic for tuberculosis treatment. Detection of these mutations helps clinicians make informed decisions about antibiotic selection, enabling personalized treatment regimens. This test is particularly valuable in cases of treatment failure, relapse, or when drug-resistant tuberculosis is suspected. Early detection of resistance mutations can help prevent the development of extensively drug-resistant tuberculosis (XDR-TB) and improve patient outcomes.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
What do the results mean?
Is this test painful?
Sources
- 1CDC - Tuberculosis (TB)Source
- 2WHO - TuberculosisSource
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.
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