13 VNTR’s, RFLP, SSR, RAPD  Every strand of DNA has stretches that contain genetic information which are responsible for an organism's development (exons) and stretches that, apparently, supply no relevant genetic information at all (introns).  Although the introns may seem useless, it has been found that they contain repeated sequences of base pairs.  These sequences are called Variable Number Tandem Repeats (VNTRs).   VNTR's also called minisatellites were discovered by Alec Jeffreys et. al. of U.K. These consist of hypervariable repeat regions of DNA having a basic repeat sequence of 11-60 bp and flanked on both sides by restriction sites.  The number of repeats show a very high degree of polymophism and the size of VNTR varies from 0.1 to 20 Kb. The length of minisatellites and position of restriction sites is different for each person.  Therefore, when the genomes of two people are cut using the same restriction enzyme, the length and number of fragments obtained is different for both.  This is called RFLP or Restriction Fragment Length Polymorphism.  These fragments, when separated by gel electrophoresis, and obtained on a Southern Blot, constitutes what is called DNA fingerprint.  Father of DNA fingerprinting is Alec Jeffreys while the Indian experts Lalji Singh and V.K. Kashyap are known as Father of Indian technique