DETECTION OF OLIGONUCLEOTIDES HYBRIDIZED TO A PLANAR SURFACE USING MATRIX-ASSISTED LASER-DESORPTION MASS-SPECTROSCOPY

The detection of oligonucleotides hybridized to a planar, plastic subs trate using matrix-assisted laser-desorption time-of-flight mass spect roscopy is reported. Oligonucleotides of length 18 to 29 bases were hy bridized to a plastic surface upon which a monolayer of an oligonucleo tide of sequence 5'-TCC TCT CTC CGT CAT GCG TAT CGT TCA AT-3' was teth ered at the 3' end. The target olignucleotides were hybridized from di lute aqueous solution. The system was prepared for laser desorption by using the matrix 3-hydroxypicolinic acid, deposited at 45 degrees C. The subsequent mass spectra revealed parent molecular ion for the targ et DNA with low-level dimerization and no discernible fragmentation.