The uptake of quantum dots (QD-5 nm particles of CdSe/ZnS-mercaptoacetic acid) by human neutrophilic granulocytes was studied using the methods of scanning laser and scanning probe microscopy. The results show that the neutrophilic granulocytes may be subdivided into three subpopulations: (1) the cells with no uptake of QD (10.0 +/- 2.0%); (2) cells that accumulate QD in their volume (28.0 +/- 1.9%), and (3) cells, surrounded by a halo of QD (59.0 +/- 2.2%). The dispersion of these characteristics may suggest the differences in neutrophilic granulocyte plasma membrane permeability.