Multicolor instrumentation for direct fluorescent detection of nucleic acids microchip

Deposition of nucleic acids on solid support in the form of high density array (a DNA microarray) creates a powerful nonelectrophoretic technology for highly parallel genetic analysis. Microarrays have applications in the areas of DNA sequencing, genetic mutation detection and gene expression monitoring. We report here the design and utility of an experimental instrument for microchip parallel hyperspectral fluorescent imaging. The instrument integrates in-line laser excitation of microarray, parallel fluorescent spectrometry with cooled CCD and dye-base spectral classification software. Instrumentation has been applied for imaging detection, spectral analysis and base classification of Genetic Bit Analysis (GBA) reactions in a microchip format on a glass support. GBA is a solid phase DNA sequence analysis method that provides single nucleotide resolution by specific extension of dye-labeled dideoxynucleotidetriphosphates (ddNTPs). GBA testing yields one or two different ddNTPs on any given microarray spot, so analysis must resolve any pair wise combination of all possible ddNTPs labeled with distinct fluorescent dyes.