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Gram Stain Bacteria Identification (Blood Culture Qualitative Probe Impedance Method)

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

This test checks for the presence of bacteria in your blood using a qualitative probe method. It helps identify infections that may require antibiotics.

Quick summary

["A simple blood test to detect bacterial infections quickly and guide treatment decisions."]

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

Key facts at a glance

LOINC
88259-7
Short code
GN bact Bld Pos Probe-Imp
Synonyms
GN bact Bld Pos Probe-Imp
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe
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

What This Test Measures

The test involves collecting a sample of your blood and applying it to a probe that detects bacterial presence through impedance. It does not measure bacterial count or specific bacteria types but confirms whether bacteria are present in your bloodstream.

How the Test Works

Your blood sample is processed to detect bacteria using a specialized probe that responds to bacterial activity. The probe measures changes in electrical impedance, which indicates the presence of bacteria. This method is typically used as a screening tool rather than a definitive identification.

Why It’s Done

This test is often used in blood culture screening to quickly identify potential bacterial infections, especially in patients with fever, signs of infection, or known risk factors for sepsis.

When Results May Be Important

Positive results suggest the presence of bacteria in your blood, which may require immediate medical attention, including antibiotic treatment. Negative results mean no bacteria were detected in this sample, but further testing may still be needed if you have symptoms of infection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Blood Culture Gram Stain Screening

Frequently asked questions

What could cause abnormal results?
A positive result may indicate a bacterial infection, such as sepsis or endocarditis. False positives can occur if there are contaminants in the blood sample. A negative result does not rule out infection entirely; other tests or follow-up may be needed.
How long will I need to wait for results?
Results from this qualitative probe method are typically available within hours to a few days, depending on laboratory processing times. Your healthcare provider will discuss the results with you and determine next steps.
Can I do anything to prepare for this test?
No special preparation is needed for this test. You may have a small needle inserted to draw blood, and you can resume normal activities afterward. If you are on antibiotics or have a history of blood infections, let your healthcare provider know.
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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