CNBr-activated Singarose 4B and CNBr-activated Singarose 4FF are cyanogen bromide-preactivated agarose resins commonly used for coupling proteins or other molecules containing primary amino groups. The coupling reaction is rapid, and the resulting affinity resin exhibits stable properties. These resins are primarily applied in the separation and purification of proteins and other biomolecules. The coupling reaction proceeds under mild conditions, enabling direct conjugation of biomacromolecules without requiring a spacer arm. The multi-point coupling ensures stable ligand attachment with minimal detachment.