Figure 1

DGS and preparation of real tags. (a) Schematic outline of DGS. Colored boxes represent genomic MboI real tags. See text for details. (b and c) Preparation (b) and characterization (c) of real tags. Representative results using genomic DNA from MKN1 gastric cancer cells are shown. (b) Short fragments of MboI-digested genomic DNA (30 to 60 bp) were electroeluted from an agarose gel (i), concatenated and subcloned. Resultant recombinant plasmids were pooled to generate the 1st library (ii). Long concatemers (140 to 800 bp) were excised from 1st library vectors, electroeluted (iii), concatenated and subcloned. The resultant recombinant plasmids represent 2nd library clones (iv). The number of tags contained in each clone is shown at the top of each lane. Inserts were examined by XhoI/SacI digestion in panels (ii) and (iv). *, vector fragments; **, SpeI/PstI digestion of the multiple-cloning site without insert. (c) Actual number of real tags from the 2nd library is shown in the histogram (left), and their characteristics are summarized (right).