A 1829 The use of DNA sequences to identify a person is called DNA fingerprinting

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from the suspect can provide evidence that the suspect was present at the scene of the crime.

The probes most commonly used in DNA fingerprinting are complementary to short sequences repeated in tandem that are widely found in the human genome (see p. 000 in Chapter 11). People vary greatly in the number of copies of these repeats; thus, these polymorphisms are termed variable number of tandem repeats (VNTRs).

Since its introduction in the 1980s, DNA fingerprinting has helped convict a number of suspects in murder and rape cases. Suspects in other cases have been proved innocent when their DNA failed to match that from the crime scenes. Initially there was some controversy over calculating the odds of a match (the probability that two people could have the same pattern) and concerns about quality control (such as the accidental contamination of samples and the reproducibility of results) in laboratories where DNA analysis is done. In spite of the controversy, DNA fingerprinting has become an important tool in forensic investigations.

DNA fingerprinting has also been used to provide information about the relationships and sources of other organisms. For example, DNA fingerprinting was used to determine that several samples of anthrax mailed to different people in 2001 were all from the same source.

www.whfreeman.com/pierce More information on DNA fingerprinting

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