Imaging liver biology in vivo using conventional confocal microscopy.

Imaging of live animals using intravital microscopy (IVM) has provided a substantial advance in our understanding of cell biology. Here we describe how to adapt a conventional, relatively low-cost laser-scanning microscope to operate as a versatile imaging station. We present the surgical procedures needed to perform liver confocal IVM in mice, thereby allowing one to image different cells in their native environment, including hepatocytes, endothelial cells and leukocytes, as well as to analyze their morphology and function under physiological or pathological conditions. In addition, we propose a plethora of working doses of antibodies and probes to stain multiple cells and molecules simultaneously in vivo. Considering the central role of the liver in metabolism and immunity and the growing interest in the relationship between immune and parenchymal cells, this protocol, in which 20 min of preparation yields up to 4 h of imaging, provides useful insights for various research fields. In addition, the protocol can be easily adapted to investigate adipose tissue, mesentery, intestines, spleen and virtually any abdominal organ.