LIFESCI 15 Lecture Notes - Lecture 9: Microsatellite, Dna Profiling, Master Sergeant
Document Summary
Real fingerprints not left behind in many crimes. Dna is a long sequence of letters that carry the info of how to build molecules for the body. On average, individuals differ in their dna sequence at 0. 1% of their bases: 3 million differences out of 3 billion base pairs. For an str locus many (2 or 3 dozen or even more!) alleles exist within the population, but each individual can only have two of them. Choose 6 features for which individuals vary a lot. Compare dna sample for the 6 features; if they are the same at all of them . Creating a dna fingerprint: the dna fragment containing each str region is amplified using pcr. This results in huge numbers of those fragments: pcr- duplicating numerous dna through heating, mixing, and cooling, the fragments are separated by size, using electrophoresis. Despite universally accepted methods, dna fingerprinting is not foolproof.
