English: Visualization of hepatocellular transport by intravital fluorescence microscopy. Sinusoidal delivery and biliary clearance of DY635, a fluorescent dye that is primarily hepatobiliary excreted, in a representative sham and septic animal 15 hours post insult. After intravenous administration of the dye, images of the same region of the liver were captured every five minutes (x40/0.6 objective lens; the liver surface was epi-illuminated with a 100-watt mercury lamp with two filter sets: i) 365- to 395-nm excitation and 445- to 450-nm emission band pass filters (DAPI filterset) were applied for visualization of the liver architecture (autofluorescence resulting from hepatocellular reduced pyridine nucleotides (NADH)); ii) 630- to 660-nm excitation and 650- to 690-nm emission band pass filters (CY5 filterset) were applied for visualization of DY635). In the sham animal, DY635 displayed a rapid uptake with immediate excretion into the bile canaliculi while excretion was impaired under conditions of sepsis.