The chemical structure of everyone's DNA is the same. The only difference between people (or any animal) is the order of the base pairs. There are so many millions of base pairs in each person's DNA that every person has a different sequence. Using these sequences, every person could be identified solely by the sequence of their base DNA fingerprinting also called DNA Typing in genetics is the method of isolating and making images of sequences of DNA (deoxyribonucleic acid). The technique was developed in 1984 by the British geneticist Alec Jeffrey’s, after he noticed the existence of certain sequences of DNA (called mini satellites) that do not contribute to the function of a gene but are repeated within the gene and in other genes of a DNA sample. Jeffrey’s also determined that each organism has a unique pattern of these mini satellites, the only exception being multiple individuals from a single zygote (e.g., identical twins).
However, because there are so many millions of base pairs, the task would be very time-consuming. Instead, scientists are able to use a shorter method, because of repeating patterns in DNA. These patterns do not, however, give an individual "fingerprint," but they are able to determine whether two DNA samples are from the same (1) person, related people, or non-related people. Scientists use a small number of sequences of DNA that are known to vary among individuals a great deal, and analyze those to get a certain probability of a