Dna probe diffraction assay and reagents

Abstract

The assay of the subject invention uses DNA sequences as probes in a nucleic acid hybridization diffraction assay, to detect specific DNA sequences in a sample. Diffraction assay methodologies are applied to determine the presence and amount of analyte. This invention involves a discovery in the areas of supporting surfaces for a biogrid or biograting which provide greatly reduced non-specific hybridization and binding. A preferred process of this invention involves manufacturing a biograting for use in a light diffraction assay, and comprises adhering a uniform layer of hybridizing reagent comprising a nucleotide sequence on a smooth, solid surface and exposing the surface to UV radiation through a shadow mask with a diffraction grating pattern of lines to selectively deactivate the hybridizing reagent, leaving a biological diffraction grating design of lines of active hybridizing reagent. The smooth, solid surface is preferably selected from the group consisting of polysilicon and single crystalline silicon surfaces. The diffraction hybridizing assay method of this invention for determining the presence or quantity of an analyte in an aqueous sample comprises contacting a nucleic acid sequence diffraction biogrid with the sample under proper circumstances and for a sufficient time to permit nucleic acid hybridization between a nucleic acid sequence probe and an analyte; separating the biogrid from the sample; illuminating the biogrid with light from a light source; and determining the light diffracted by the diffraction hybridization assay surface.