Karius Test | Karius

Karius Test

Karius® Test


Discover Clarity in Full Bloom


Pathogens can be hard to uncover–find them fast with the Karius Test.

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The Karius Test is a blood test based on next-generation sequencing of microbial cell-free DNA. It can identify and quantify over 1,000 clinically relevant pathogens including bacteria, DNA viruses, fungi, and parasites. Applications include complicated pneumonia, infections in immunocompromised patients, and endocarditis.



Detecting pathogens with the Karius Test improves infectious disease diagnosis



Higher diagnostic yield1

The Karius Test demonstrates superior yield when compared to blood culture and other microbiological testing.




Faster time to diagnosis1

The Karius Test can identify etiologies of infections more rapidly than the standard-of-care diagnostic workup.





The Karius Test helps diagnose deep-seated infections such as invasive fungal infections from a single blood draw.





Clinical Applications





Immunocompromised patients

Invasive fungal infections

Viral infections

Neutropenic fever



 other cardiovascular infections




View Clinical Data



Karius Test Performance


The clinical and analytical validation of the Karius Test was published in Nature Microbiology. It is a landmark validation study for a metagenomic infectious disease diagnostic test.




Analytical Specificity


per pathogen



Analytical Sensitivity


at 50 fragments of cell-free DNA per μL plasma


View Validation Data



The Karius Test detects microbial cell-free DNA in the blood–detecting both bloodstream and deep-seated infections


During an acute infection, pathogens leave microbial cell-free DNA (mcfDNA) in the blood. Even when an infection is localized, mcfDNA from the infection can be detected. Detection of mcfDNA in the blood is a breakthrough in the diagnosis of infectious diseases, and mcfDNA offers several advantages over conventional testing:




Detection of infections throughout the body

mcfDNA can be found in the bloodstream even in deep-seated infections.




Breadth and depth of organisms

mcfDNA from multiple organisms can be found in the blood. The Karius Test detects over 1,000 pathogens – DNA viruses, bacteria, fungi, and eukaryotes.




Quantitative results

mcfDNA concentration corresponds with pathogen abundance over time.

High-quality process ensures both speed and accuracy with results delivered typically the next day


The Karius Test is a send-out test ordered by the clinician. The patient’s specimen is collected at the hospital and shipped to Karius.


Specimen Collection
and Shipping Instructions


Once the specimen arrives at Karius, specimen processing to reporting takes 1 day*.





Step 1
Specimen Collection

5 mL standard blood draw in Plasma Preparation Tube



Step 2
Specimen Processing

DNA extraction and library preparation



Step 3

Microbial cell-free DNA sequencing



Step 4

Curated clinical-grade pathogen database



Step 5

Quantitative amounts of clinically relevant pathogens

Sample Test Report


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*More than 85% of specimens received by 8:30 am (PT) Monday through Saturday are reported the next day.


Bacteria detected

Highlighted Bacteria:

Nocardia species (72)
Legionella species (42)
Rickettsia species (18)
Actinomyces species (15)
Mycoplasma species (12)
HACEK organisms (including Aggregatibacter actinomycetemcomitans,
Aggregatibacter aphrophilus,
Aggregatibacter segnis,
Cardiobacterium hominis,
Eikenella corrodens,
Haemophilus aegyptius,
Haemophilus parainfluenzae,
Kingella denitrificans and
Kingella kingae)
Streptobacillus moniliformis
Mycobacterium tuberculosis complex
Mycobacterium avium complex (MAC)
Mycobacterium chimaera


Comprehensive pathogen detection of over 1,000 bacteria, DNA viruses, fungi, molds and eukaryotes.


Pathogen List


1. Blauwkamp T, et al. Nat Microbiol. 2019;4(4):663-674.

2. Armstrong AE, et al. Pediatr Blood Cancer. 2019;66(7).

3. Hong DK, et al. Diagn Microbiol Infect Dis. 2018;92(3):210-213.