[The synthesis and mass spectrometry of oligonucleotides bearing thiophosphoryl modifications of the predetermined localization].

The technique of parallel automated synthesis of oligodeoxynucleotides bearing various local thiophosphoryl internucleotide bonds was optimized using assembling in the standby mode and creation of special program blocks. The selected conditions of Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI TOF MS) provided an increase in the method sensitivity (up to 1-10 fmol of oligonucleotide in sample) and registration of reliable spectra of oligodeoxynucleotide thiophosphoryl analogues. This enables to reliably prove the presence of the specified number of thiophosphoryl bonds within synthetic sequences.