PART I: DNA FINGERPRINTING DNA
fingerprinting has many applications. It is now routinely used to test samples of blood, hair, saliva and semen left at crime scenes. The results are compared to those of a suspect to establish the individual’s guilt. DNA fingerprinting can also be used to establish familial relationships in paternity cases, to track hereditary diseases, and to identify the best matches for organ transplants. This procedure can even be used to ascertain the level of inbreeding in endangered animals and to determine how newly discovered species are related to other organisms on Earth. DNA Fingerprinting is a method of identifying individuals based on the unique RFLP’s (restriction fragment length polymorphisms) of their DNA. When DNA is extracted from white blood cells (or other body tissue) and treated with a restriction enzyme, the enzyme cuts the DNA wherever it finds the sequence of 4-8 bases specific to that restriction enzyme.1 This produces a set of DNA fragments of different lengths. (Polymorphism means “having many forms” – in this case many different lengths.) Different people have very different DNA fingerprints because they have very different distances between the base sequences cut by the enzyme.