Patent ID: 6861216

Claim:
A process for detecting a complementary DNA fragment which comprises the steps of: bringing a liquid phase comprising single-stranded sample DNA fragments having a radioactive label into contact with a DNA micro-array having a support and at least two defined areas in each of which a group of probe compounds selected from the group consisting of DNA molecules, DNA fragments, synthesized oligonucleotides, synthesized polynucleotides, and PNA (peptide nucleic acid) are fixed under such condition that a group of the probe compounds fixed in one area differs from a group of the probe compounds fixed in another area, so that DNA fragments complementary to a group of the probe compounds are fixed to an area of the micro-array by hybridization of complementary DNA fragments to the probe compounds; removing unfixed sample DNA fragments from the DNA micro-array; keeping the DNA micro-array in contact with a radiation image storage panel containing a stimulable phosphor via a spacer sheet intervening between the DNA micro-array and the radiation image storage panel, said spacer sheet being in direct contact with the micro-array and having openings aligned with the ares of the micro-array to which the probe compounds are fixed, so that the radiation image storage panel can absorb and store radiation energy transmitted by the radioactive label of the fixed complementary DNA fragments through the openings in said spacer sheet; irradiating the radiation image storage panel with a stimulating light, so that the image storage panel releases a stimulated emission from the area in which the radiation energy is stored; detecting the stimulated emission photoelectrically to obtain a series of electric signals; and processing the electric signals to locate the area in which the complementary DNA fragments are fixed.