DEPArray™ is a cell microarray implementing Silicon Biosystems’ patented technology for individual cell manipulation and detection.
The base of DEPArray™ is a microelectronic active silicon substrate embedding control circuitry for addressing each individual dielectrophoretic (DEP) cage. The unprecedented flexibility and selectivity afforded by this device represent a breakthrough in biological research and analysis.
Due to the small size of the electrodes in the chip, DEP cage sizes can be set to accommodate one single cell, thus enabling individual manipulation of a large number of cells. The device embeds more than 300,000 20μmx20μm electrodes, which can be used to create up to 76,800 DEP cages in a tiny volume of about 11μl.
The Silicon Biosystems technology platform works with samples of a few microliters and analyzes solutions containing from 1 to 100,000 cells. An important aspect of the DEPArray is the absence of stress on cells during manipulation. Cells maintain viability, their DNA is completely intact and their proliferation capability is unmodified. It is a transversal technology offering different possible applications such as prenatal and cancer diagnosis, cell therapy and single cell resolution biology.

Key capabilities vs. available FACS are:

• sort specific cells wich are extremely rare in the original suspension, based on relative fluorescence  parameters combined with morphology
• sort cells from a suspension where the total cell count is extremely low
• no need for a-priori thresholds, pick-up only best cells available in the sample
• no contamination from spurious events verifying images associated to cells selected from the scatter plot or histogram, including fluorescence and bright-field
• sort by morphological parameters such as shape, nucleus to cytoplasm ratio, fluorophores co-localization, thanks to image based selection

Applications:

• Rare-cell sorting: isolation of  pure Circulating Tumor Cells, or fetal cells circulating in maternal blood, with image-based selection.
• Cell-sorting of small cell-loads: starting sample may range from tens to tens of thousands of cells.
• Investigation of cell-cell interaction: as an example, the study of cell lysis mechanism induced by cytotoxic cells.
• Single cell immunophenotyping: by using functionalised microbeads and target cells, it is possible to determine the phenotype of a cell and sort it.
• Drug delivery: one may also deliver into the cell tiny amounts of compounds encapsulated within liposomes.

 Additional features:

• Individual-cell operation: unprecedented selectivity and flexibility
• Programmability: the analytical protocol can be digitally controlled by a computer program, enabling straightforward automation and customization.
• No sticking: cells are manipulated in a contacts-less fashion while they are kept in levitation inside the microchamber, thus preventing them from sticking to the device surfaces.
• No clogging: DEPArray™ channel-less architecture does not rely on capillaries or micromachined channels, and is thus less prone to clogging. Even if clogs occur, cells can easily be routed around the obstacles.