A DNA probe pl-79 is homologous to at least a portion of a hypervariable DNA region located at chromosome lp36.3 in the human genome. The DNA region displays extensive restriction fragment length polymorphisms when digested with certain restriction endonucleases. Probe pl-79 is believed to have a repeated 39 base sequence CCTGGGGGTGNGNGTGCTGTTCCAGGCTGTCAGAGGCTC, and can be used as a genetic "fingerprint" to establish human identity, determine engraftment of bone marrow transplants, determine parentage, and otherwise map genes.