This work is focused on the synthesis and characterization of targeted libraries of multifunctional probes (MuD) for cell biology studies. The MuD probes generic structure can be dissected in the following functional domains (see figure): Fluorescent Domain, for studies with fluorescence microscopy; Ultrastructural Domain, for studies with electron microscopy; Dendritic Domain, provide site-isolation of each domain and allow the systematic variation of properties such molecular weight, solubility, etc.; Variable domain (not shown), will add further functionalities and diversity as needed. The cell biology studies will be performed in collaboration with Prof. Ed Rosa-Molinar from the Department of Biology, at the UPR-Río Piedras.