Synthesis of oligodeoxynucleotides containing N4-mercaptoethylcytosine and their use in the preparation of oligonucleotide-peptide conjugates carrying c-myc tag-sequence.

The preparation and properties of oligodeoxynucleotides containing mercaptoethyl groups at position N-4 of cytosine are described. The resulting thiol-oligodeoxynucleotides were reacted with a maleimido-peptide carrying the c-myc tag-sequence. The peptide-oligonucleotide conjugate is specifically recognized by an anti c-myc monoclonal antibody, thus constituting a labeling system with sensitivity similar to other existing methods of nonradioactive labeling.