LAUSR

Significance Antibiotic therapy within 3 h of initial symptom-based recognition can significantly reduce mortality in blood stream infections and bacteremia. However, blood cultures, which remain the gold standard for pathogen detection, can take up to 5 d for a confirmed negative result. Here, we report a culture-free “biphasic” approach to performing amplification reactions directly from whole blood. We dry the blood and create a physical nano scale fluidic network inside the dried blood matrix to allow for DNA amplification. We show single-molecule sensitivity for 3 bacteria and 1 fungal species from ~1 mL of blood in <2.5 h. We validated the assay with clinical samples and found complete agreement with the results of the clinical laboratory that used blood culture and PCR.