Balgramstn
A microscopic examination of lung fluid to detect and identify bacteria causing respiratory infections.
{"Examines fluid from the lungs collected during bronchoscopy","Uses special staining to identify bacteria under a microscope","Helps diagnose lung infections like pneumonia or bronchitis"}
Key facts at a glance
- LOINC
- 105916-1
- Short code
- BALGS
- Synonyms
- BAL Gram Stn
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof, screw-cap container (50 mL conical tube); sterile collection cup suitable for BAL specimens
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- gram-stain
- CPT
- 87205
- SNOMED
- 168537006
- Specimen volume
- Minimum 5 mL of bronchoalveolar lavage fluid; optimal volume 10-50 mL for adequate analysis
- Stability
- Room temperature: 1 hour; Refrigerated (2-8°C): 24 hours. Specimen should be processed as soon as possible after collection to preserve bacterial viability and cell morphology.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 1–4 hours
- Order
- routine
What is this test?
This test examines a sample of fluid from your lungs (bronchoalveolar lavage or BAL) using a Gram stain technique. During a bronchoscopy, a thin tube with a camera is passed through your mouth or nose into your lungs. Saltwater is flushed into a specific area of the lung and then collected back for laboratory analysis. The sample is then stained with special dyes and examined under a microscope to look for bacteria.
How is the sample collected?
The sample is collected through a procedure called bronchoscopy. Your doctor will insert a flexible tube (bronchoscope) through your nose or mouth, down your throat, and into your lungs. Saltwater (saline) is infused into the lung area being examined and then suctioned back out. This fluid contains cells and any microorganisms from your airways and air sacs.
What does the Gram stain show?
Gram stain is a laboratory technique that colors bacteria purple or pink. This helps doctors determine the type of bacteria present: Gram-positive bacteria (purple) or Gram-negative bacteria (pink). This information is crucial because different bacteria require different antibiotics for treatment.
Reference range
No bacteria observed; normal respiratory flora absent or scant; minimal white blood cells (predominantly macrophages). Results reported as: Negative, Rare, Few (1+), Moderate (2+), Many (3+), or Numerous (4+) organisms per low power field.N/A
Patient should be prepared for bronchoscopy per institutional protocol. Typically requires fasting for at least 6 hours prior to the procedure. Informed consent must be obtained. Sedation may be administered. Bronchoalveolar lavage is performed by instilling and aspirating sterile saline through a bronchoscope.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is bronchoscopy painful?
How long does it take to get results?
Do I need to fast before this test?
What are the risks of bronchoscopy?
Sources
- 1
- 2
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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