Interactions of oligonucleotide derivatives with mammalian cells and cellular biopolymers have been investigated. The derivatives were oligonucleotides bearing an alkylating 2-chloroethylamino group at the 3′-end and a cholesterol residue at the 5′-terminal phosphate. These compounds are readily taken up by cells and react with cellular DNA, RNA and some proteins which may play a role in delivery of the compounds into cells.
