3'-Amino-Modifier CPGs, containing amino groups protected with the base-labile Fmoc group, are designed to functionalize the 3’-terminus of the target oligonucleotide by the introduction of a primary amine. In an alternative approach, the nitrogen destined to become the 3’-amino group is included in a phthalimide (PT) group which is attached to the support through an amide group attached to the aromatic ring. This simple linkage is very stable to all conditions of oligonucleotide synthesis and contains no chiral center. Using an extended ammonium hydroxide treatment (55°C for 17 hours), the cleavage of the amine from the phthalimide is accomplished along with the deprotection of the oligonucleotide. ABI-style columns are supplied unless otherwise requested.