Analyzing Unamplified Gene Sequences with High Density Optical Fiber Arrays

We have developed rapid, selective, and extremely sensitive assays for labeled and unlabeled oligonucleotides utilizing high-density fiber-optic microarrays. Microarrays are prepared by randomly distributing DNA-functionalized 3 µm-diameter microspheres in an array of wells etched in a 500 µm diameter optical imaging fiber. The fluorescence responses of the individual microsphere elements in the array are monitored by an imaging fluorescence microscope system. With labeled targets, hybridization was observed with a detection limit of 10 zmol DNA in 10 µL. With unlabeled targets, distinction between amplified genomic WT507 and AF508 Cystic Fibrosis samples was observed.