The problem of subclone identification for DNA fragments of a known nucleotide sequence has been considered. We suggest a strategy for rapid identification of a large number of subclones based on: (i) partial sequencing of the subclone DNA (single nucleotide track); (ii) representation of the result in the form of a numeric code showing the distribution of the chosen nucleotide along the sequence; and (iii) identification of the subclone sequence using this code in a catalogue compiled and printed for a whole DNA sequence. The same approach is applicable when the subclones are expected to have homology with known sequences.