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Bacteriaidentified16srrnaspecseq

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

A molecular test that identifies bacteria by sequencing their genetic material when standard culture methods cannot.

Quick summary

{"Uses genetic sequencing to identify bacteria that are difficult or impossible to grow in lab cultures","Helps diagnose infections when standard tests are negative or inconclusive","Can detect multiple bacterial species from a single sample","Results typically take longer than routine culture (several days to weeks)","Useful for blood, tissue, fluid, and sterile body site samples"}

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

Key facts at a glance

LOINC
66885-5
Short code
16SRRNA
Synonyms
Bacteria identified 16S rRNA Spec Seq
Category
chemistry
Sample
serum
Container
Sterile, DNA-free, nuclease-free collection tube (e.g., cryovial or sterile screw-cap microcentrifuge tube). For serum: red-top or serum separator tube (SST) free of preservatives. Tubes should be properly labeled with patient identifiers, specimen source, and collection date/time.
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
sequencing
CPT
87153
SNOMED
104377003
Specimen volume
Minimum 1 mL of serum. Optimal volume 1-2 mL for adequate bacterial DNA extraction and analysis.
Stability
Serum should be processed within 2 hours of collection. Refrigerate at 2-8°C if processing is delayed beyond 2 hours. Frozen specimens stable at -20°C for up to 30 days; for longer storage, maintain at -70°C to -80°C. Avoid repeated freeze-thaw cycles as DNA degradation may compromise detection sensitivity.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
48–168 hours
Order
routine

What is this test?

The 16S rRNA gene sequencing test is a sophisticated molecular technique that identifies bacteria by analyzing their genetic material. The 16S rRNA gene is a component of bacterial ribosomes that contains unique genetic sequences specific to different bacterial species. Unlike traditional culture methods that require growing bacteria in a lab, this test can detect and identify bacteria directly from your sample by reading their genetic code.

How is it performed?

A sample is collected from your body (such as blood, tissue, fluid, or other sterile sites). In the laboratory, technicians extract bacterial genetic material (DNA) from the sample. They then amplify and sequence the 16S rRNA gene region. The resulting genetic sequence is compared to databases of known bacterial DNA to identify what organisms are present.

Why might I need this test?

Your doctor may order this test when: standard bacterial cultures have failed to grow anything despite signs of infection, you have a serious infection and quick identification is needed, there is suspicion of multiple bacterial species, the infection involves organisms that are hard or impossible to grow in standard lab conditions, or you have been on antibiotics that may have affected culture results.

Reference range

Not Detected - No bacterial DNA identified in the specimen. Positive results are reported with bacterial genus and species identification when sequence match criteria are met (typically ≥99% sequence identity and ≥500 base pairs).N/A

Specimen: serum

No special patient preparation required. Specimen should be collected prior to initiation of antimicrobial therapy whenever possible. For serum specimens, collect before antibiotic administration to maximize pathogen detection. Inform the laboratory of current or recent antimicrobial use.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

How long does it take to get results?
Results typically take 3-7 days, but may take up to 2-4 weeks in some cases. The complex nature of genetic sequencing and analysis requires more time than standard bacterial cultures.
Is this test better than regular bacterial culture?
It is not necessarily better, but complementary. Standard culture remains the first-line method because it is faster and provides live bacteria that can be tested for antibiotic sensitivity. 16S rRNA sequencing is used when culture fails or cannot be performed.
Does this test detect all types of bacteria?
The test detects most common bacteria but may not identify all species. Some bacteria have very similar 16S rRNA sequences, making precise identification difficult. Additionally, the test may not detect viruses, fungi, or parasites.
Will this test tell me which antibiotics will work?
Not directly. While it identifies the bacterial species, antibiotic sensitivity testing typically requires growing the bacteria in culture. Your doctor will use the identification result along with clinical judgment and other available information to choose appropriate treatment.
Is the test safe?
The test itself is safe. The safety primarily depends on how the sample is collected (blood draw, tissue biopsy, etc.), not on the laboratory test itself.
  1. 1
    Mayo Clinic Laboratories - Test CatalogSource
  2. 2
    American Society for MicrobiologySource
  3. 3
    National Institutes of Health (NIH) - Genetics Home ReferenceSource

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