Describe how genetic fingerprinting is carried out? (example of 6-mark question)

Every individual's DNA sequence is different and genetic fingerprinting can be used to distinguish individuals based on their unique DNA sequence. To begin, DNA needs to be extracted from a sample, which could be either blood, skin or hair follicle. DNA is cut into segments using restriction endonucleases whilst also leaving intact micro-satellites. DNA probes complementary to micro-satellites are added. The mixture pipetted into wells on gel and an electric current is passed through enabling the separation of DNA fragments by gel electrophoresis. X-ray film is used to identify the areas with the probe and therefore identify the unique pattern of fragments.