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Microbiological culture and sensitivity of blood (aerobic and anaerobic)

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

This test helps detect and identify bacteria or fungi present in your bloodstream, which may indicate an infection.

Quick summary

["Blood cultures can confirm infections and guide treatment choices."]

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

Key facts at a glance

LOINC
90435-9
Short code
Microorg prel grow Bld Ql Aerobe Cult
Synonyms
Microorg prel grow Bld Ql Aerobe Cult
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
aerobic-culture
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

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like fever, chills, or unexplained fatigue, or if you’ve been exposed to a serious infection. It’s also used to monitor people with weakened immune systems or chronic conditions that increase infection risk.

What to Expect During the Test

A small amount of blood is drawn from a vein, usually in your arm. The blood is placed in special containers to grow bacteria or fungi over time. Results take days to weeks, depending on the organism’s growth.

Preparation for the Test

No special preparation is needed, but inform your provider about any medications or recent illnesses. Avoid antibiotics if possible, as they may affect results.

What the Results Mean

Positive results show the presence of bacteria or fungi in your blood. These findings help doctors choose the right antibiotics or antifungal treatments. Negative results mean no obvious infection was detected in the sample drawn.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Blood cultures are critical for diagnosing serious infections like sepsis, endocarditis, or bloodstream infections from medical devices. Early identification allows for prompt treatment to prevent complications like organ damage or death.

Short name

Blood Culture Screening

Frequently asked questions

How long does it take to get results?
Results typically take 3–7 days for preliminary findings, with final identification of organisms taking up to 10–14 days. Some labs use rapid methods for initial detection.
What if my blood culture comes back positive?
If bacteria or fungi are found, your doctor will prescribe antibiotics or antifungals tailored to the identified organism. Follow-up tests may be needed to monitor treatment effectiveness.
Can I take antibiotics before my blood culture?
No, antibiotics can interfere with results. If you’ve taken them recently, inform your provider immediately to discuss alternative testing or timing.
  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