Improvement of the dideoxy chain termination method of DNA sequencing by use of deoxy-7-deazaguanosine triphosphate in place of dGTP

The dideoxy chain termination method using deoxy-7-deazaguanosine triphosphate (dc7GTP) in place of dGTP was found to be very useful. Sequencing of a part of the human N-myc gene having 85% GC content is impossible by the original method using dGTP, because of compression of bands. However, the nucleotide sequence of this part was unambiguously determined by analysis of both strands by the modified method. Use of dc7GTP is concluded to improve the dideoxy chain termination method for DNA sequencing.