An array of hollow microcapillaries for the controlled injection of genetic materials into animal/plant cells

A micromachined system is described with the aim of controlled injection of DNA into cells is proposed. The injection system is composed of two components; the hollow microcapillaries for injection and the microchambers for cell trapping. The hollow microcapillaries part has been fabricated and tested. Bosch deep RIE etching was used to etch small and deep holes, approximately 5 /spl mu/m in diameter and 100 /spl mu/m in depth, on a silicon substrate and makes it possible to fabricate microcapillaries with microchannels inside. The fabricated and tested hollow microcapillaries are 1 /spl mu/m in thickness, 30 /spl mu/m in length and 5 /spl mu/m in diameter and made of SiO/sub 2/. The height of microcapillaries can be easily controlled. The silicon substrate with microcapillaries is bonded anodically with a processed glass substrate, enables the silicon membrane to endure the pressure from outside when DNA injection. Through backside silicon etching in TMAH solution and making holes on tips of microcapillaries, the process of hollow microcapillaries is completed. Using the hollow microcapillaries, fluorescent dye (DAPI) has been injected into plant cell conglomerates (tobacco, BY-2) in order to confirm that fluidic material can be injected via microchannels. High injection label was confirmed and no noticable deterioration of microcapillaries was observed after injection operation.