TentaGel® resins are grafted copolymers consisting of a low crosslinked polystyrene matrix on which polyethylene glycol (PEG or POE) is grafted via an ethyl ether group which increases stability towards acid treatment and minimizes PEG-leaching. The graft copolymer shows modified physicochemical properties which are highly dominated by the PEG moiety (and no longer by the polystyrene matrix) and has hydrophobic and hydrophilic properties. These copolymers are pressure stable and can be used in batch processes as well as under continuous flow conditions. The PEG spacer is in the range of MW 3000 Da. TentaGel® resins have high diffusion rates and excellent swelling in a wide range of solvents from e.g. toluene to water. TentaGel® Macrobeads are highlighted by extraordinary large particle diameters and high capacities based on the TentaGel® technology and designed for single bead synthesis and single bead analysis. This resin is derived from TentaGel® NH2 resin by coupling with the 4-carboxytrityl linker. For further reactions the alcohol group has to be converted to the chloride and then used immediately. It is an ideal support for coupling sensitive amino acids like Cys, His or Pro since no razemization as well as no diketopiperazine formation occurs. Cleavage is in general achieved by using either 5 - 50% TFA in DCM (containing 5% triisopropylsilane) or acetic acid.