MALDI-TOF mass spectrometric method for detection of hybridized DNA oligomers

Two new approaches for nucleic acid hybridizations by MALDI-TOF mass spectr ometry are described. Hybridization using genomic DNA without polymerase ch ain reaction sns demonstrated. Total genomic DNA of bacteriophages bound to charge-modified nylon membranes was identified by the hybridization of spe cies-specific oligonucleotide probes, lambda -Phage DNA and M13 were used f or the test with good success. Since MALDI-TOF mass spectrometry c;tn be us ed to measure the molecular weights of different probes, mass spectrometry can be used for the detection of hybridizations with multiple probes. We de monstrate that multiple-probe hybridization can be resolved by mass spectro metry.. Six probes with different mass tag were used for hybridization on a single spot. MALDI-TOF mass spectrometry was successfully used to measure these probes simultaneously. This provides a simple nonradioactive method f or multiplex hybridization analysis. It has the potential to drastically in crease the speed for microarray hybridization analysis hl the future.