Nano-meter sized particles of de-aluminated zeolite Y has a high adsorption capacity of both low molecular weight bio-molecules and macromolecules. In this study we used de-aluminated zeolite Y as a novel approach to study the mechanisms of endocytosis in immature human peripheral blood dendritic cells (DCs). Probes detecting pH neutral and acidic endosomes were adsorbed to the zeolite and used as a tracer of the endosomal pathway of a cell in the form of acidification and lysosomal function. Both the myeloid (M-DCs) and the plasmacytoid (P-DCs) dendritic cell subsets showed an endocytosing capacity comparable to peripheral blood monocytes but only the M-DCs were able to form acidic endosomes after internalization of zeolite particles. Furthermore, during lipopolysaccharide (LPS) stimulation of the DCs population, an enhanced induction of acidic endosomes was only seen in the M-DC population. Proteolytic degradation of endocytosed proteins was detected using self-quenched DQ-ovalbumin adsorbed to zeolite particles and our results showed a clear difference between the two DC populations. The M-DC population, that showed formation of acidic endosomes, also showed proteolytic degradation of ovalbumin. The P-DC population on the other hand, showed no formation of acidic and no proteolytic degradation of ovalbumin. Various bio-molecules can be adsorbed by de-aluminated zeolites and in conclusion we propose the use of zeolite particles as a useful tool in the study of the endocytosing mechanisms of a cell.