Exosomes (1 μg/μL) were labeled with DiI (1,1′-Dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate) or DiR (1,1'-Dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide) by incubation with the dyes (1 mM) at the ratio of 500:1 in volume for 5 min at 37°C. The free dye was removed by additional exosome isolation with ultracentrifugation.
For in vivo tracing of exosomes, mice were subcutaneously injected with 200 μg of the indicated DiR-labeled exosomes. The localization of the exosomes in different organs was detected by imaging with the IVIS Lumina II in vivo imaging system (PerkinElmer, Thermo Fisher, USA).
To visualize the location of exosomes in TDLNs and other tissues, the DiI-labeled exosomes were injected. The colocalization between DiI signals and cell markers (stained with corresponding antibodies) was examined under a Nikon A1 Spectral Confocal Microscope (Nikon, Japan).
For in vivo tracing of exosomes, mice were subcutaneously injected with 200 μg of the indicated DiR-labeled exosomes. The localization of the exosomes in different organs was detected by imaging with the IVIS Lumina II in vivo imaging system (PerkinElmer, Thermo Fisher, USA).
To visualize the location of exosomes in TDLNs and other tissues, the DiI-labeled exosomes were injected. The colocalization between DiI signals and cell markers (stained with corresponding antibodies) was examined under a Nikon A1 Spectral Confocal Microscope (Nikon, Japan).