fluorescent probe for fluid-phase endocytosis

[N.P.Dantuma at biol.ruu.nl]

Hi,

I would like to visualize fluid-phase endocytosis using fluorescense 
microscopy. There are many dyes which can be used for this purpose. So the 
major problem is which dye to use. It would be very nice if I could use this 
probe in combination with a DiI-labeled ligand (excitation=550, emission=
570).
Suggestions with respect to dyes, concentrations and references are welcome.

Thanks, 

Nico Dantuma
Biochemical Physiology
Utrecht University
The Netherlands