In Vivo Lymph Node Imaging: FIGURE 1.

Abstract

INTRODUCTIONImaging the single-cell dynamics of the immune system within an intact environment requires the ability to look deep inside tissues and organisms with spatial and temporal resolutions adequate to track cell morphology, motility, and signaling processes, all while minimizing perturbation of the system under study. Fluorescence techniques are highly suited for this purpose, permitting both labeling of specific cells, organelles, or proteins and functional readout of physiological events, and two-photon microscopy allows these processes to be visualized within native tissue environments. Although intravital immunoimaging requires invasive surgery to access the tissue or organ of interest, these preparations have the advantage of keeping blood and lymphatic flow intact. In the procedure for in vivo imaging of the inguinal lymph node (LN) described here, a rubber O-ring is glued onto a skin flap so as to form a fluid chamber for the dipping microscope objective. This arrangement also helps stabilize the tissue mechanically without interrupting circulation.