DNA testing is one of the most accurate assessments of identifying individuals as well as what individuals are related to each other. This has led to much more accuracy in paternity testing as well as in solving criminal cases.
DNA is deoxyribonucleic acid and is found in the cells of the body. It is the blueprint that determines biological characteristics and is derived half from each parent. Each person's DNA is unique to that individual. DNA testing provides answers to questions such as the paternity of a child as well as to identify what individual was in a particular locale.
How DNA Tests Are Performed
Samples are collected independently and sent to a laboratory that specializes in DNA testing. Samples can either be hair, saliva, cells from the inside of the cheek, blood or anything that may contain DNA. The DNA is then extracted and purified from other components in the sample. The DNA is then run through a process called polymerase chain reaction (PCR) to amplify the sections of DNA. This amplification process copies the microsatellite markers within the DNA millions of times to ensure there are enough copies for testing. Once the markers have been amplified, they are placed into an automatic DNA analyzer which separates them by size. After these results are gathered, statistical analysis is performed upon the donors for all the DNA markers for each specific test. These results are then given to the person who requested the test.
Legal Admissibility of DNA Tests
As well as having several ways to perform DNA tests, there are also two different types of tests: a home test and a legal test. A home-based DNA test is typically cheaper due to lack of collection fees and notary signature, and is private and convenient because the test can be preformed within your own home. These tests are not admissible in court due to a lack of chain of custody. For a DNA test to be admissible in court, the samples need to be collected by an impartial third party and chain of custody rules for the handling of the samples need to be followed. The test needs to be performed by a laboratory that is accredited by a body designated by the federal Secretary of Health and Human Services.
DNA Testing for Relationships
In custody and child support cases, DNA tests are usually called paternity tests and are used to determine whether a particular man is the biological father of a child. Testing can be done before the baby is born by chorionic villus sampling (CVS) as early as the 10th week of pregnancy or about the 15th week with amniocentesis.
Other applications of a paternity test can include the identification of an adopted child's biological family, confirmation of parentage of children conceived by in vitro fertilization, and matching the biological parents to newborns who might be switched at birth accidentally.
In other cases, DNA relationship tests are performed in order to show a family relationship between the two people sampled. Examples of this include determining parentage for insurance or inheritance claims, confirming relationships of reunited brothers and sisters and proving a familial relationship to a citizen of a particular country in order to qualify for immigration status.
DNA Testing for Crime-Solving
While DNA evidence is taken in to consideration in newer criminal cases, there is a movement for DNA testing in older cases, especially ones involving the death penalty. According to The Justice Project, "post-conviction DNA testing has led to the exoneration of more than 200 wrongfully convicted individuals in the United States."