Understanding Your Diagnostic Lab Test: What It Is, How It Is Done, and Why It Matters for Your Health
A laboratory test that identifies and characterizes specific types of bacteria from a sample to determine the exact strain causing an infection.
{"This test identifies the specific type of bacteria causing an infection","Helps doctors choose the most effective antibiotic treatment","Results guide infection control measures in healthcare settings","Sample is collected from the infected area or blood (serum)","Results typically available within several days to a week"}
Key facts at a glance
- LOINC
- 612-2
- Short code
- BCSUB
- Synonyms
- Bacteria Islt Subtyping
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container or transport medium appropriate for the source (e.g., culturette swab, sterile screw-cap tube, blood culture bottle)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- bacterial-subtyping
- CPT
- 87153
- SNOMED
- 442126005
- Specimen volume
- Variable depending on specimen source; minimum 0.5 mL for liquid specimens or adequate tissue/swab material
- Stability
- Transport to laboratory within 2 hours at room temperature for most specimens; refrigerate at 2-8°C if delay exceeds 2 hours; frozen at -70°C if extended storage required
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–168 hours
- Order
- routine
This is a laboratory test that helps your healthcare provider learn important information about your health by analyzing a small sample, such as blood, urine, or tissue, that is collected during your visit and examined by trained laboratory professionals.
The Bacterial Strain Typing test, also known as bacterial subtyping or bacterial strain identification, is a laboratory procedure that analyzes a sample to identify the specific strain or type of bacteria present. This goes beyond simply detecting that bacteria are present—it determines exactly what kind of bacteria is causing your infection, which is crucial for determining the most appropriate treatment.
The test is performed by collecting a small sample from your body, most often through a simple blood draw from a vein in your arm or by asking you to provide a urine sample, and the sample is then sent to a laboratory where it is carefully analyzed and the results are reported to your provider.
A sample is collected from your body—typically from the site of infection (such as a wound, urine, or respiratory secretions) or from blood serum. In the laboratory, technicians use various methods to grow (culture) the bacteria and then identify its specific strain using techniques such as biochemical testing, molecular methods (like PCR), or mass spectrometry. The LOINC code 612-2 refers specifically to bacterial strain identification in bacterial isolates.
This test is important because it gives your healthcare provider objective information about how your body is functioning, which supports an accurate diagnosis, helps monitor an existing condition over time, and guides decisions about the most appropriate treatment plan for your specific needs.
Knowing the exact strain of bacteria helps your healthcare provider select the most effective antibiotic. Some bacterial strains have developed resistance to certain antibiotics, so identifying the specific strain ensures you receive the right medication. Additionally, this information helps public health officials track infection patterns and prevent the spread of resistant bacteria.
Reference range
Not applicable; result reported as identified bacterial strain type or subtypeN/A
No special patient preparation required. Specimen collection should be performed prior to initiation of antimicrobial therapy whenever possible to maximize recovery of organisms
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Bacterial strain typing is clinically significant for several reasons: (1) It guides antibiotic selection by identifying which medications will be effective against the specific bacteria causing infection; (2) It helps detect antibiotic-resistant bacteria, such as MRSA (methicillin-resistant Staphylococcus aureus) or ESBL-producing organisms; (3) It assists in outbreak investigation by determining if infections in different patients are caused by the same strain; (4) It provides prognostic information, as some strains are more virulent than others; and (5) It informs infection control measures in hospitals and long-term care facilities to prevent transmission.
Frequently asked questions
Is the test painful?
How long does it take to get results?
Do I need to fast before this test?
What happens after the results come back?
Can this test detect antibiotic resistance?
Sources
- 1
- 2
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