A human chromosomal region, 15q11-q13, was microdissected, its DNA was amplified with the primer-linker PCR method, and the PCR products were cloned into a plasmid vector to construct a microclone library. Of 193 microclones analyzed with Southern blot hybridization on hybrid cell panels, 26 (13.5%) were either single-copy (unique) or low-repetitive fragments. By screening of a cosmid library of human genomic DNA using the 26 microclones as probes, 47 positive cosmids were obtained and underwent regional mapping with chromosome fluorescence in situ hybridization (FISH). Sixteen cosmids gave FISH signals at 15p-cen, 5 at 15q11-q13, 6 at 15q22-q26, 3 at other chromosomes, and 17 no signal. These 27 cosmids mapped to chromosome 15 are useful additions to the inventory of DNA markers of this chromosome including the much interested Prader-Willi/Angelman syndrome region.