Preliminary results. (A) Diagram of flow conditions for hepatocytes in collagen gel in the microfluidic device. PDMS, polydimethylsiloxane. (B) Microfluidic channels 50 μm wide, 10 mm long, and 100 μm tall with grooves to represent a liver sinusoid. (C) Phase image of primary hepatocytes in a microgrooved channel . (D), (E) Live primary rat hepatocytes stained for live (celcein)/dead (ethidium homodimer-1) cells at days 3 and 9. (F) Fixed primary rat hepatocytes stained for intracellular albumin (anti-rat albumin antibody; Abcam, Cambridge, MA, USA). (G), (H) Primary human hepatocyte sentinel cells expressing reactive oxygen species (ROS) biosensor treated with dimethylsulfoxide (DMSO; control) or 100 μmol menadione for approximately 4 hours. (I), (J) Primary human hepatocyte sentinel cells expressing mitochondrial function biosensor treated with DMSO (control) or 100 μmol menadione, approximately 16 hours after addition of treatments.