Restriction mapping of phage lambda vectors using non-radioactive methods

In order to take advantage of non-radioactive methods, we have developed two plasmids (p lambda LE and p lambda RE) for mapping restriction sites of long inserts cloned in phage lambda vectors. These plasmids are constructed by cloning the left 402-bp and right 560-bp phage lambda genome ends, respectively. To map restriction sites, the cloned sequences in p lambda LE and p lambda RE are labeled with digoxygenin and hybridized to partially digested lambda DNA. The ladder of bands detected with these probes can be used to construct restriction maps in the same way as those obtained using radioactively labeled cos complementary oligodeoxyribonucleotides [Rackwitz et al., Gene 30 (1984) 195-200].