Oligodeoxyribonucleotide activation with 2,4-phenylenediisothiocyanate andtheir covalent grafting onto amine-functionalized latex microspheres

The activation of various synthetic oligodeoxyribonucleotides (ODNs), heari ng a hexamethylamine arm at their 5'-end, with the 2,4-phenylenediisothiocy anate (PDC) was studied. The activation reaction had to be performed within 40 min, because of competitive hydrolysis of the isothiocyanate functions. ODN modifications were then characterized by different analytical methods i.e. gel capillary electrophoresis, Matrix-Assisted Laser Desorption-Ioniza tion-Time of Flight (MALDI-TOF) mass spectrometry. Moreover, activation of the amine groups of the nucleic bases was evidenced through the chemical an alysis of the enzymatic-digested conjugate (PDC-ODN) by reverse phase HPLC Preliminary results on the covalent grafting of activated ODN molecules ont o the aminated latex particles showed that the amount of grafted ODNs was d irectly related to the number of potential grafting sites on the nucleic ac id probe (primary amine group of hexamethyl arm and amine functions of the nucleic bases).