8-Amino-2'-deoxyguanosine incorporation into oligomeric DNA

During the incorporation of 8-amino-dG into oligomeric DNA, the deprotection conditions previously recommended (28% ammonia at room temperature) do not effect complete removal of the dimethylaminomethylene protecting groups. At elevated temperatures oxidative degradation of the oligomer and exchange of ammonia with dimethylamine in the protecting group at C8 occurred. The resolution of these problems and a method to obtain a series of homogeneous oligomers in reasonable yield containing 8-amino-dG located site-specifically are described.