DNA profiling is a quick way to compare DNA sequences of two or more different organisms.
1) Isolation of DNA
Identical twins have the exact same DNA as they come from the same egg fertilised by the same sperm. Yet, their fingerprints are not the same ---> hence fingerprints do not depend on genes, they depend of the environment.
2) Cutting, sizing and sorting. Special enzymes called restriction enzymes, or "gene extractors", are added to cut the DNA at specific restriction sites. E.g. ATCGATTGC (CUT) ATCGATTGC (CUT) repeats of the core sequence. This creates different repeats of the same DNA sequence.
They are then sorted according to size through gel electrophoresis. Placed on wells in gel (seeweed agarose), placed under electric current. DNA segments move towards the positively charged cathode at different speeds. The smaller DNA segments move farther and faster.
*to separate molecules of different sizes, chromatography is also a suitable technique
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