Blood and bacteria-based experiments
Healthy blood samples were collected from the blood center GeBlod, Stockholm, Sweden in EDTA tubes. PEO was used to dilute blood in 1:10, 1:5, and 1:2 dilutions. Inlets and outlets were centrifuged at 5000 g for 10 min to pellet bacteria and resuspended into equal volumes of PEO.Escherichia coli ATCC 25922 strain (E.coli ) andStaphylococcus capitis (Staph ) was grown separately on blood agar plates (3 sets of plates from each outlet per experiment) for 12 hr. at 37 °C incubator. Optical density was measured using an Ultrospec 10 cell density meter (Amersham Biosciences, UK) at 600 nm after inoculating bacteria from the blood agar plate into PEO. Bacteria were fluorescently labelled using the Backlight viability kit (ThermoFischer, Sweden) before spiking into blood for the purpose of visualization and to check their viability. Green fluorescence depicts viable bacteria while red fluorescence indicates dead ones.