The isolation of rare cells, such as fetal nucleated red blood cells and trophoblasts, from maternal blood for non-invasive prenatal diagnosis is a new field of research exhibiting several difficulties since this strategy requires unresolved basic technological protocols for a successful outcome. However, several achievements in the field of Laboratory-on-a-chip (Lab-on-a-chip) technology have provided clear advancements in projects aimed at the isolation of rare cells from biological fluids. Among the most interesting approaches are those based on dielectrophoresis (DEP). DEP-based Lab-on-a-chip platforms have been demonstrated to be suitable for several applications in biotechnology and biomedicine. DEP-based arrays are able to manipulate single cells, which can be identified and moved throughout the DEP chip to recovery places. DEP buffers are compatible with molecular interactions between monoclonal antibodies and target cells, allowing integration of these devices with magnetic cell sorting (MACS). DEP treatment does not alter the viability of manipulated cells.