A liquid biopsy that avoids diagnostic impasse for life-threatening infections

Infections are one of the leading causes of morbidity and mortality in immunocompromised patients.

Clinical Care

The main clinical application for the Karius Test is to help physicians diagnose infections in immunocompromised patients. The test helps diagnose pneumonia, invasive fungal infections, culture-negative endocarditis, opportunistic infections, and infectious causes of neutrophenic fever.

Lab Services

The Karius Test provides you and your clinical team with the ability to use only a single blood draw to rapidly, and with high accuracy, detect more than 1000 clinically relevant pathogens.

A Rapid Liquid Biopsy for Infectious Disease

The Karius Test is a liquid biopsy that can non-invasively and rapidly detect over 1000 pathogens causing both deep-seated and bloodstream infections from a single blood sample. The Karius Test helps clinicians avoid invasive, low-yield, and sequential diagnostic tests that can delay treatment for the most vulnerable hospitalized patients.

The main clinical application for the Karius Test is to help physicians diagnose infections in immunocompromised patients

Invasive Fungal Infections
Infectious Causes of Neutropenic Fever
Opportunistic Infections

The Karius Test improves diagnosis and management of life-threatening infections

Reduce complications from invasive procedures with 1 blood sample

The Karius Test requires 1 single blood draw to reveal information-rich, microbial cell-free DNA, potentially avoiding 63% of invasive diagnostic procedures.1

Speed up diagnosis of infections with a 1-day turnaround time

The Karius Test results typically report the next day after sample receipt, compared to standard methods, which can take days or weeks to yield results.

Optimize antimicrobial treatment

The Karius Test results have led to a change in antimicrobial management in 59%-75% of cases.2, 3

Testing Process

From blood sample to report, the Karius Test Process typically offers next day turnaround service.

Clinical and Analytical Validation

Multiple published studies demonstrate the efficacy and clinical impact of the Karius Test.

Frequently Asked Questions

From clinical situations to sample collection to interpretation of results, find more specific information about Karius and Karius Test.

Improve the diagnosis of life-threatening infections

The Karius Test has demonstrated higher diagnostic yield than the standard of care diagnostic tests in multiple studies.

Karius Test diagnostic yield



SOC diagnostic yield


Use CasePatient PopulationKarius YieldSOC YieldReference
Febrile neutropenia55 adult patients with leukemia



Benamu E et al. Clin Infect Dis. Published online April 19, 2021. Epub ahead of print.

Prolonged/persistent fever, or imaging susoicious of infection31 adult patients with hematologic malignancy +/-BMT



Yu J et al. Transplant Cell Ther. Published online February 26, 2021. Epub ahead of print.

Focal/systemic infections79 pediatric patients (76% immunocompromised


(63% invasive)


(48% invasive)

Rosoff J et al. Open Forum Infect Dis. 2019;6(8)

Febrile neutropenia, pneumonia, or intra-abdominal infection10 adults with chemotherapy or transplant



Camargo JF et al. F1000Res. 2019 Jul 26;8:1194

Invasive infections / FUO / FN / culture-negative endocarditis167 adult patients (36% immunocompromised)​


7% (Blood Culture only)

Francisco D et al. IDWeek Online 2020, October 22-25, 2020

Focal/systemic infections (Retrospective analysis of use)​110 Pediatric patients​



Wilke J et al. BMC Infectious Diseases. 2021;21:552

Complicated community acquired pneumonia​46 pediatric patients 



Dworsky ZD, et al. Hosp Pediatr. 2022 Mar 2:e2021006361.​

Infective endocarditis10 pediatric patients​


30% (Blood Culture) / ​50% (All)​

To RK et al. Pediatr Infect Dis J. 2021;40(5):486-488​

Karius Test Process

Karius Test reports are typically available 1 day after specimen receipt*

The Karius laboratory is CLIA-certified and CAP-accredited to perform high-complexity clinical laboratory testing

*>85% of specimens received by 8:30 AM (PT) Monday through Saturday are reported the next day

Step 1


5-mL standard blood draw in plasma preparation tube

View specimen collection and preparation instructions

Step 2


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

View Sample Test Report

Consultations are available with Karius infectious disease physicians and clinical microbiologists.

Ordering the Karius Test

The Karius Test is a send-out test that can be ordered by hospital clinicians. The patient's blood sample is collected at the hospital and shipped to the Karius laboratory overnight.

The kit includes:

  • Plasma preparation tube
  • Shipping materials
  • FedEx® Pak with preprinted label to Karius

1. Rossoff J et al. Open Forum Infect Dis. 2019;6(8); 2. Francisco D et al. IDWeekOnline 2020, October 22-25, 2020; 3. Yu J et al. Transplant Cell Ther. Published online February 26, 2021.