Patent ID: 8278427

Claim:
A spacer molecule comprising a donor region which can be bonded to a 3′-terminal end of nucleic acid, a polyethylene glycol (PEG) region that is bonded to the donor region and comprises polyethylene glycol as a main component and a peptide acceptor region which is bonded to the PEG region and comprises a member selected from the group consisting of puromycin, 3′-N-aminoacylpuromycin aminonucleoside, and 3′-N-aminoacyladenosine aminonucleoside, wherein the donor region is deoxycytidylic acid or dideoxycytidylic acid, 5′-terminal end of the donor region being monophosphated, and wherein the PEG region is bonded to the donor region directly or via one or two residues of functionally modified deoxyribonucleotide or ribonucleotide.