High density arrays

Abstract

The invention provides a method for generating arrays with a variety of densities, in particular, high density arrays. Generally, the method includes a printing step and an illumination step. In the printing step, a predetermined volume of a reagent solution containing receptor molecules is applied to a solid support in a desired pattern. In one embodiment, the receptor molecule is derivatized with a photoreactive agent. In an alternate embodiment, the solid support includes a photoreactive agent. In a preferred embodiment, the receptor molecule is a nucleic acid. In the illumination step, the photoreactive groups are irradiated to immobilize the receptor molecule to the solid support. In one embodiment, a mask having the same center to center distance (e.g., pitch) as the printed spots, but a smaller diameter, is placed over the printed pattern and illuminated. Preferably the mask illuminates a spot having a smaller diameter than the printed spots. Thus, according to the invention, the immobilized reagent spot has a smaller diameter than the original printed spot. In an alternate embodiment, the illumination step can be carried out using mirrored laser technology. If desired, the application and illumination of offset spots can be repeated to form a high density array.

Dependencies are inferred from the claim text.