A scheme for sequencing large DNA molecules by identifying local nuclear-induced effects

An experimental scheme for sequencing large DNA molecules is proposed where DNA strands are replicated, with all nucleotides of a given kind marked with radioactive 32P. The marked strands are affixed to an appropriate substrate and are kept until most 32P atoms decay. The local damage caused by the decay is expected to allow the identification of the sites occupied by that particular nucleotide, using atomic scale microscopy (scanning tunneling or atomic force microscopy). Quantitative aspects and methodological considerations associated with the proposed scheme are discussed.