Understanding Your Laboratory Test: What It Is, How It Is Performed, and How to Prepare
A blood culture test detects bacteria in your blood to diagnose serious infections like sepsis.
{"A blood culture test checks if bacteria are present in your blood","It helps diagnose bloodstream infections and sepsis","Results typically take 2-5 days to complete","Multiple blood samples are usually collected from different veins"}
Key facts at a glance
- LOINC
- 48727-2
- Short code
- BCID2
- Synonyms
- Bacteria Bld Cult org #2
- Category
- chemistry
- Sample
- whole-blood
- Container
- Aerobic and anaerobic blood culture bottles (e.g., BacT/ALERT or BACTEC blood culture bottles); typically paired sets recommended for adults
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- culture
- CPT
- 87040
- SNOMED
- 104193008
- Specimen volume
- 8-10 mL per bottle for adult blood culture bottles; 1-3 mL for pediatric bottles; total volume recommended 20-30 mL per blood culture set
- Stability
- Bottles should be incubated within 2 hours of collection. If delayed, hold at room temperature (20-25°C); do not refrigerate. Stable up to 24 hours at room temperature prior to incubation.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 48–120 hours
- Order
- routine
What is this test, and why might my doctor have ordered it for me?
A blood culture test is a laboratory procedure that detects bacteria in your blood. When bacteria or other harmful microorganisms enter your bloodstream, they can cause serious infections such as sepsis or bacterial endocarditis. This test helps your healthcare provider identify the specific type of bacteria causing the infection, which guides treatment decisions.
How is this test performed, and what can I expect during the procedure?
A healthcare professional will draw blood from a vein, usually in your arm. To increase accuracy, multiple blood samples are often collected from different sites. The blood samples are then placed in special culture bottles and sent to a laboratory where they are monitored for bacterial growth over several days.
How should I prepare for this test, including any steps to take beforehand?
No special preparation is needed for a blood culture test. You can eat and drink normally before the test. Inform your healthcare provider about any antibiotics you are currently taking, as this may affect the results.
Reference range
No growth of pathogenic bacteria. Normal blood is sterile. Identification of organism reported when isolated (e.g., Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, etc.)N/A
No special patient preparation required. Skin antisepsis is critical at collection site. Use proper aseptic technique to prevent contamination. Disinfect venipuncture site with chlorhexidine or 70% isopropyl alcohol followed by povidone-iodine, allowing adequate drying time before collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
How long does it take to get results?
Does a positive result always mean I am sick?
Is the test painful?
Why do I need multiple blood draws?
Sources
- 1
- 2
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