We have analyzed human cellular DNA for its delta--and beta-globin gene sequence content by separation of restriction enzyme fragments by agarose gel electrophoresis; transfer of the DNA fragments to nitrocellulose filters; hybridization of filters with 32P--beta-globin cDNA; and analysis by autoradiography. A short cDNA has been used to identify specifically the 3' end of the genes and to orient the fragments. A comparison of the globin gene fragments generated by normal and Lepore DNA has been used to distinguish fragments representing DNA sequences between the delta and beta genes and those containing sequences flanking either 5' to the delta gene or 3' to the beta gene. The results indicate that unique restriction fragments are presented in normal DNA and absent in Lepore DNA, and allow preliminary ordering of these fragments on a restriction enzyme map. In addition, the Lepore, delta--and beta-globin genes have been found to contain at least one inserted nucleotide sequence of about 1000 bases which is not represented in mature globin mRNA.