Recovery of DNA Fragment from a DNA Probe Array

Molecular biology is moving rapidly towards the stage of functional genomics in which rapid preparations of expressed messages (mRNA) will be required. If a DNA library is constructed on a solid support (DNA probe array) and any kind of expressed messages can be individually recovered from the probe array, DNA probe array will become a very useful method. Consequently, we developed a DNA preparation method using a DNA probe array that utilizes photo-thermal denaturation to recover specific DNA. The protocol for preparing DNA probe array was investigated to realize the stable immobilization of DNA probes on the surface of solid support. We used a glass plate coated with Cr (5-10 nm thick). The Cr surface was modified with 3-glysidoxypropyltrimethoxysilane to introduce active residues that can couple with amino residues at the 5' termini of DNA probes. The Cr surface acts as a photo-thermal transducer. The preparation method of DNA uses infrared (1053-nm) laser irradiation to thermally denature and release DNA immobilized in a specific area of a DNA probe array. Different DNA fragments fixed in place on the DNA probe array could be separately recovered. There were enough quantities of recovered DNA that can be amplified by using PCR.