Understanding Your Medical Test: A Patient's Guide to What It Is, Why It Is Needed, and What Your Results Mean
A laboratory test that detects and identifies anaerobic bacteria in your blood to diagnose infections.
{"This test looks for harmful bacteria that grow without oxygen in your bloodstream","It helps doctors diagnose serious blood infections (bacteremia) caused by anaerobic bacteria","A blood sample is taken from a vein and sent to the lab for culture","Results typically take 2-5 days as bacteria need time to grow","Positive results help doctors choose the right antibiotic treatment"}
Key facts at a glance
- LOINC
- 17934-1
- Short code
- BLDCULAN
- Synonyms
- Bacteria Bld Anaerobe Cult
- Category
- chemistry
- Sample
- whole-blood
- Container
- Aerobic and anaerobic blood culture bottles (paired set recommended; e.g., BacT/ALERT SN and SA bottles, or BACTEC Plus Anaerobic/F and Standard/10 Aerobic bottles). Each bottle should be inoculated with 8-10 mL of blood in adults.
- Units
- N/A
- Ref low
- 5
- Ref high
- 7
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- anaerobic-culture
- CPT
- 87075
- SNOMED
- 104200001
- Specimen volume
- Adults: 20-30 mL total per blood culture set (8-10 mL per bottle, 2-3 bottles per set); Pediatric: 1-10 mL total depending on patient weight; Neonates: 0.5-1 mL per bottle. Volume is critical for organism recovery.
- Stability
- Blood culture bottles must be incubated as soon as possible after collection. If immediate transport to laboratory is not feasible, bottles should be kept at room temperature (18-25°C) and transported to the laboratory within 2 hours of collection. Do not refrigerate or incubate at site. Once in the laboratory, bottles are continuously monitored in the blood culture instrument for up to 5-7 days.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 120–168 hours
- Order
- routine
This test is a diagnostic procedure that measures specific substances or functions in your body to help your healthcare provider evaluate your health. It provides important information that supports accurate diagnosis, guides treatment decisions, and helps monitor existing medical conditions over time.
The Blood Anaerobe Culture test is a laboratory procedure that detects and identifies anaerobic bacteria in your blood. Anaerobic bacteria are microorganisms that can survive and multiply without oxygen. This test is specifically designed to grow and identify these bacteria, which can cause serious infections in the bloodstream.
Your doctor may order this test to investigate symptoms you have been experiencing, to confirm or rule out a suspected condition, or as part of a routine checkup. It can also be used to track how well a treatment is working or to screen for potential health problems before symptoms appear.
Your doctor may order this test if you have symptoms of a blood infection, such as fever, chills, rapid heartbeat, or confusion. It is particularly important when a bacterial infection is suspected but standard blood cultures do not show results. Anaerobic bacteria can cause infections in wounds, abdominal cavity, or other body areas that can spread to the bloodstream.
The test is typically performed by a trained healthcare professional in a laboratory, clinic, or hospital setting. Depending on the type of test, a small sample of blood, urine, or other body material may be collected, or a specialized device may be used to gather the information your doctor needs.
A healthcare professional will draw a blood sample from a vein in your arm. The sample is then placed in special culture bottles that provide an environment without oxygen, allowing anaerobic bacteria to grow. The lab monitors the culture over several days to see if bacteria multiply. If bacteria grow, they are identified through additional testing.
During the test, you can expect the process to be relatively quick and comfortable. If a blood sample is needed, you may feel a brief pinch when the needle is inserted. A member of your care team will explain each step, answer your questions, and make sure you remain comfortable throughout the procedure.
The blood draw is quick and may cause slight discomfort or bruising at the puncture site. Multiple blood samples may be needed for accurate results. There is no special preparation required for this test. After the blood is drawn, you can resume your normal activities immediately.
Your results will show whether your measurements fall within the normal reference range for your age and sex. Values outside that range do not always mean something is wrong, so your healthcare provider will review the findings with you, explain what they mean in context, and discuss any follow-up steps.
A negative result means no anaerobic bacteria were detected in your blood sample. A positive result indicates that anaerobic bacteria were found and identified. Your doctor will use this information to determine the appropriate treatment, including which antibiotics will be most effective against the specific bacteria identified.
Reference range
Negative for anaerobic bacterial growth. No anaerobic bacteria isolated after 5-7 days of incubation. Identification reported when clinically significant anaerobic organisms (e.g., Bacteroides, Clostridium, Peptostreptococcus, Fusobacterium, Prevotella) are recovered.N/A
No special patient preparation or fasting required. However, skin antisepsis at the collection site is critical. Use chlorhexidine gluconate or povidone-iodine for skin disinfection. Allow antiseptic to dry completely (at least 30-60 seconds) before venipuncture. Collect prior to starting antimicrobial therapy whenever possible, but do not delay collection if patient is already on antibiotics.
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 negative result mean I don't have an infection?
Is this test painful?
Will I need to do anything special before the test?
What happens if the test is positive?
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