Oligo™ R3 bulk resin is a rigid polymeric bead designed for reversed-phase chromatography of polynucleotides and other biomolecules. The combination of 30-μm particle size, resistance to high pH, and high-phase ratio, makes Oligo R3 resin particularly suited to preparative purification of synthetic oligonucleotides and peptides. The packing consists of cross-linked poly-divinylbenzene particles.