LIGHT-GENERATED OLIGONUCLEOTIDE ARRAYS FOR RAPID DNA-SEQUENCE ANALYSIS

In many areas of molecular biology there is a need to rapidly extract and analyze genetic information; however, current technologies for DNA sequence analysis are slow and labor intensive. We report here how mo dern photolithographic techniques can be used to facilitate sequence a nalysis by generating miniaturized arrays of densely packed oligonucle otide probes. These probe arrays, or DNA chips, can then be applied to parallel DNA hybridization analysis, directly yielding sequence infor mation. In a preliminary experiment, a 1.28 x 1.28 cm array of 256 dif ferent octanucleotides was produced in 16 chemical reaction cycles, re quiring 4 hr to complete. The hybridization pattern of fluorescently l abeled oligonucleotide targets was then detected by epifluorescence mi croscopy. The fluorescence signals from complementary probes were 5-35 times stronger than those with single or double base-pair hybridizati on mismatches, demonstrating specificity in the identification of comp lementary sequences. This method should prove to be a powerful tool fo r rapid investigations in human genetics and diagnostics, pathogen det ection, and DNA molecular recognition.