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Bacteria Identification by Culture and Susceptibility Testing (Serum/Plasma)

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

This test checks for the presence of bacteria in your blood or plasma and helps determine which antibiotics could effectively treat any infection.

Quick summary

["Identifies potential blood infections and guides antibiotic treatment choices."]

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

Key facts at a glance

LOINC
73666-0
Short code
B-Hem Strep Islt LA
Synonyms
B-Hem Strep Islt LA
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
la
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Does

A blood sample is cultured to detect bacteria that may have entered your bloodstream. If bacteria are found, the test also assesses their sensitivity to various antibiotics to help your healthcare provider choose the best treatment.

How the Test Works

Your blood or plasma sample is placed in a controlled environment to grow any bacteria present. After incubation, the test identifies bacterial growth and determines antibiotic resistance patterns using standard laboratory methods.

When You Might Need This Test

This test is typically ordered if you have symptoms of a blood infection (e.g., fever, chills, rapid heartbeat), a known bacterial infection, or if you’re at higher risk (e.g., weakened immune system, recent surgery).

Preparation for the Test

No special preparation is usually needed, but inform your provider about any medications you’re taking, as some may affect results or increase infection risk.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results confirm a bacterial blood infection, prompting immediate treatment with targeted antibiotics. Negative results mean no bacteria were detected, but further evaluation may still be needed if symptoms persist. Timely identification helps prevent complications like sepsis.

Short name

Bacteria Culture & Antibiotic Sensitivity

Frequently asked questions

Why might my doctor order this test?
Your doctor may order this test if you have symptoms like fever, unusual fatigue, or signs of infection, especially if they suspect a bacterial infection in your bloodstream.
How long does it take to get results?
Results can take several days to a week, depending on the growth and testing time needed for bacterial identification and antibiotic sensitivity.
Can I take antibiotics before getting this test?
No, taking antibiotics before testing may prevent accurate detection of bacteria. Always follow your doctor’s instructions and avoid antibiotics unless prescribed.
  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