Incorporation of 7-deaza dGTP during the amplification step in the polymerase chain reaction procedure improves subsequent DNA sequencing.

An improved method for sequencing human genomic DNA amplified by the polymerase chain reaction (PCR) procedure is described. The portion of the genome investigated is the 383 nucleotide-long exon 2 of the human antithrombin III gene. Incorporation of the analogue of dGTP, 7-deaza-2'-deoxyguanosine-5'-triphosphate, during the amplification of exon 2 by PCR allowed for the elimination of recurrent artifacts obtained during sequencing of the amplified DNA by the dideoxyribonucleotide chain termination method.