Abstract: Composition, systems and methods are provided for quantifying the amount of protein aggregation occurring in a cell in vitro and in vivo. These compositions, systems and methods find use in a number of applications, including in screening candidate agents for activity in modulating intracellular and extracellular protein aggregation in vitro and in vivo; in the generation of in vivo data for modeling aggregation processes in the cellular environment; for the validation of in vitro data, e.g. the effect of point mutations on the aggregation of amyloidogenic proteins; for the proteomic analysis of interacting partners so as to identify new therapeutic targets; for the analysis of changes in gene expression that are induced by intracellular versus extracellular aggregation; and for the evaluation of changes in the activity of the cellular network that controls protein folding and aggregation, the so-called proteostasis network.