Variable number tandem repeats

Variable number tandem repeats (VNTR) are short nucleotide sequences ranging from 14 to 100 nucleotides long that are organized into clusters of tandem repeats. Clusters of such repeates are scattered at many on all chromosomes. Each variant is an allele and they are inherited codominantly.

Coupled with PCR, VNTRs have been very effective in forensic crime investigations. When VNTRs are cut by restriction enzymes and the results are visualized with a Southern blot, a pattern of bands unique to each individual is produced. The likelihood of two individuals having the same band pattern is near impossible.