Micropatterning of single cell arrays using the PEG-Silane and Biotin–(Strept)Avidin System with photolithography and chemical vapor deposition

Bio-MEMS technique of organizing cells in single cell arrays makes it easier to observe cells’ individual characteristics and behaviors, which is of benefit for basic cell research and high throughout drug screening. We utilized photolithography and chemical vapor deposition (CVD) to pattern hydrophobic hexamethyldisilazane (HMDS) islands and hydrophilic polyethylene glycol (PEG)-Silane regions on 25 mm × 25 mm glass slides. Compared with methods presently used, the photoresist wells can be more stable, and clear HMDS island arrays can be formed. We adopted a better and more powerful medium, the Biotin–(Strept)Avidin System to fix cells on the specified regions of the substrate. This is more efficient than the former medium, antibodies and antigens. Moreover, using a biotinylating cell surface, we produced more biotins on the surface of the cells and made it easier to capture cells and avoid washing away fixed cells. By changing the concentration of cell suspension for seeding, we found a suitable concentration (5 × 106 cells/ml), at which the cell occupation was greater than 90%. By comparing various diameters of streptavidin islands, optimal diameters (14–20 μm) were found to capture single human promyelocytic leukemia cells (HL-60). With all optimal parameters, single cell arrays were formed. The ratio of islands capturing only one cell was approximately 77%, which is better than similar approaches.