The use of genomic DNA-based techniques in ecological and evolutionary studies has been limited by the availability of suitable probes for species of interest due to the technical difficulty of isolating and applying such probes. We have developed a simple technique that directs polymerase chain reaction (PCR) amplification to regions rich in variable number of tandem repeats (VNTRs). By using published VNTR core sequences as primers in PCRs, fragments were amplified that showed little variation within a species, but did show differences between species. When the amplified fragments were used as probes with genomic DNA Southern blots they produced hypervariable single-locus or few-locus patterns in fish, birds, and humans. We have named this procedure as Directed Amplification of Minisatellite-region DNA (DAMD).