Landmark analysis of cosmids for identifying overlapping clones. (a and b) Digestion patterns of cosmid clones with MluI (lanes 1 to 14), MluI plus BamHI (lanes 15 to 28), and MluI plus SalI (lanes 29 to 42). (c and d) Digestion patterns of cosmid clones with MluI (lanes 1 to 10), MluI plus BamHI (lanes 11 to 20), MluI plus SalI (lanes 21 to 30), and MluI plus StuI (lanes 31 to 40).