Fig. 1.

Successfully synthesized and purified siRNA-L₂ conjugate binds to albumin. (A) Abbreviated structures of reactants and final oligonucleotide-L₂ conjugate. (B) MALDI-TOF mass spectrometry of the original amine-modified siRNA, the DBCO intermediate, and the L₂ conjugate. (C) Albumin binding measured by gel stained for siRNA (Top) and protein (Bottom). siRNA-L₂ migrates as a micellar population alone and comigrates with albumin, whereas unmodified siRNA does not migrate with albumin. Note that albumin shows up as multiple bands due to running in nondenaturing, native gel conditions.