Although the introns may seem useless, it has been found that they contain repeated sequences of base pairs.
Every human being has some VNTRs.
To determine if a person has a particular VNTR, a Southern Blot is performed, and then the Southern Blot is probed , through a hybridization reaction , with a radioactive version of the VNTR in question. The pattern which results from this process is what is often referred to as a DNA fingerprint . Because VNTR patterns are inherited genetically, a given person's VNTR pattern is more or less unique. The more VNTR probes used to analyze a person's VNTR pattern, the more distinctive and individualized that pattern, or DNA fingerprint, will be.