At the genetic level we humans, we are all almost identical. Although differences between human genes are insignificant compared with the size of the human genome, modern technologies for decoding DNA sequences can detect and identify these differences.
The uniqueness of each human genetic code can be a feature that makes the decoding procedure in a very useful tool in many applications, the identification based on DNA or Paternity to forensics and criminal investigations.
Specialists in this area can recover and extract DNA samples from the small samples of human tissue. Once a sample was obtained, sufficient in quantity and adequate as quality, begins a process in many steps, called "DNA electrophoresis", highlighting the smallest differences at the molecular level, in the case of a genetic sequence.
The steps of "DNA electrophoresis" are:
Initially, specialized enzymes are used to chemically separate the "wires" of DNA, at specific positions, in the genetic sequence structure.This process results in DNA fragments of different sizes for different people. These DNA fragments are immersed in a special gel, where is applied an electrical current. DNA fragments of different sizes are moving through the gel at different speeds, when applying electric current. The result is a specific distribution of DNA in colloidal solution, on it's base the "owner" of DNA being identified .The model thus obtained is a so-called "DNA fingerprint" unique to each individual.