Development of a universal DNA fingerprinting technique using microarray technology

Advancements in technology have made it possible to print and visualize thousands of sequences of DNA on a glass slide (DNA Microarray). Specially designed DNA Microarrays with different oligonucleotide sequences were printed. These sequences do not self cross-hybridize and extend over the entire thermodynamic range of the Tm (melting temperature). KS+ plasmid was used as model sequences. These labeled probes were hybridized onto our designed microarray slides and slowly melted by heating or by washing with stringent buffers. The image of the slide was taken at each time point to give a movie of different spots disappearing at different rates. This movie acted as a "Hybridization Profile" of the plasmids. Different DNA structures were designed and attached to silicon surface. Atomic force microscopy was used to confirm the attachment of DNA structures to the silicon surface. In the future, microarrays with several thousands of designed oligonucleotides will be printed on silicon surface and then used to generate different "Hybridization Profile" of the entire genome of closely related organisms like E. Coli and Anthrax using electrical methods.