subject: Identifying a Body with DNA Sequence Analysis [print this page] Identifying a Body with DNA Sequence Analysis
Whenever human remains are recovered, one of the first tasks of a coroner is determining the identity of the body. This is especially true when the person is believed to have died of natural causes or where the cause of death is known. If the body is in good condition, a friend or relative may be used to identify, the body, as well as fingerprints and dental records. When the body has deteriorated to the points that the other methods are unable to be used, specialists may turn to various DNA tests to determine the identity, such as sequence analysis.
Sequence analysis is anything that is connected to identifying higher biological meaning using a raw sequence of data. A DNA sequence is a succession of letters that represent the primary structure of a DNA molecule or strand. There are four possible letters, each of which represents the four nucleotide bases of a DNA strand. These nucleotide bases are adenine, cytosine, guanine, and thymine. This sequence can be used in conjunction with other methods to help forensic labs identify a body that may otherwise remain unidentified.
DNA sequence analysis is a method that determines the order of nucleotide bases, cytosine, thymine, and adenine in a DNA molecule. Thanks to advances in technology, figuring out the DNA sequence of genes has become much easier to do. Knowledge of these sequences of genes within organisms has been to put to good use in diagnostic and forensic research, and is also used in basic research used to study biological systems.
By using sequence analysis on mitochondrial DNA on human skeletal remains, scientists are able to identify bodies may have otherwise remained identified. For instance, in 1984 the Vietnamese government returned a body to the United Stated government. It was believed that the body was 24 years old at the time of testing. The scientists originally performed DNA typing methods using genomic DNA, HLA-QD alpha and the variable number of tandem repeat locus D1S80. These methods were unsuccessful using the polymerase chain reaction. After these tests were unable to identify the body, an amplification of a portion of the mitochondrial DNA control region was performed. The product of this test was then subjected to DNA sequence analysis. The sequence generated from the remains was identical to the maternal reference sequence, and so the family could be found and the body identified.
The aforementioned case isn't a unique situation. There have been numerous cases where conventional DNA typing was unavailable, and so a sequence analysis was necessary in order to determine the identification of human remains. These instances have rendered this particular type of sequence analysis indispensable to forensic labs and specialists.
