Karius is a life science company focused on advancing diagnostic science and technology 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 main clinical application for the Karius Test is to help physicians diagnose infections in immunocompromised patients. The test can help diagnose pneumonia. invasive fungal infections, culture-negative endocarditis, opportunistic infections, and infectious causes of neutropenic fever.