Understanding Your Laboratory Test: A Patient Guide to Testing, Sample Collection, and Results
This test identifies and grows bacteria from a sputum sample using aerobic culture methods to diagnose respiratory infections.
{"A sputum culture helps identify the bacteria causing your respiratory infection","The test involves collecting mucus from your airways and sending it to a laboratory","Results help your doctor choose the right antibiotic treatment","Results typically take 2-3 days","Proper sample collection is important for accurate results"}
Key facts at a glance
- LOINC
- 17896-2
- Short code
- BCTSP5
- Synonyms
- Bacteria Spt Aerobe Cult org #5
- Category
- chemistry
- Sample
- sputum
- Container
- Sterile, leak-proof, wide-mouth container with screw-cap lid (sputum cup); transport medium container if delayed transport is anticipated
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- aerobic-culture
- CPT
- 87077
- SNOMED
- 448931000124102
- Specimen volume
- 2-5 mL of expectorated sputum
- Stability
- Room temperature: 2 hours; refrigerated (2-8°C): 24 hours; do not freeze. If transport is delayed beyond 2 hours, refrigerate or place in transport medium.
- TAT
- 48–168 hours
- Order
- routine
What is this test, and why might my healthcare provider recommend it for me?
A sputum aerobic bacterial culture is a laboratory test that detects and identifies bacteria in mucus from your lungs and airways. The term 'aerobic' means the bacteria are grown in the presence of oxygen. This test helps doctors determine if a bacterial infection is causing your respiratory symptoms such as cough, fever, or difficulty breathing.
How is the sample collected, and what can I expect during the collection process?
You will be asked to cough deeply to produce sputum (mucus) from your lungs. It is important to avoid saliva or nasal secretions. You may be asked to rinse your mouth with water before collecting the sample to reduce contamination. The sample is then placed in a sterile container and sent to the laboratory for analysis.
What happens in the laboratory after my sample is collected and sent for analysis?
In the lab, the sputum sample is placed on growth media and incubated in conditions that allow aerobic bacteria to grow. Technicians observe which bacteria grow and perform additional tests to identify the specific type. If bacteria are found, sensitivity testing may be done to determine which antibiotics will be most effective.
Are there any risks, side effects, or complications associated with this test?
This test carries minimal risks. You may experience some discomfort or gagging when coughing deeply to produce the sample. There is a very small risk of bleeding from the airways, especially if you have a lung condition. The test itself does not expose you to radiation or harmful substances.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Patient should rinse mouth with water prior to specimen collection to reduce contamination by oral flora. Ideally, specimen should be collected before antibiotic therapy is initiated or just before the next dose. If possible, collect in the early morning upon rising as sputum accumulates overnight in the lower airways.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is crucial for diagnosing bacterial pneumonia, bronchitis, and other respiratory infections. Identifying the specific bacteria allows doctors to prescribe targeted antibiotic treatment rather than using broad-spectrum antibiotics. This helps ensure effective treatment, reduces antibiotic resistance, and minimizes side effects. The test is particularly important for patients with severe, recurrent, or hospital-acquired infections.
Frequently asked questions
How long does it take to get results?
Do I need to fast before this test?
What if no bacteria are found?
Is this test painful?
Sources
- 1
- 2
- 3
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