Discover How DNA Testing Works

DNA testing is widely used. It is used to solve crimes and to determine maternity and paternity. But this article is not going to go into all of the uses of DNA testing but rather the dynamics of how DNA testing works regarding parental status, primarily paternity.

What is DNA Testing?

DNA testing is all about the DNA fragments which are called genetic loci. Here's how the process breaks down: Enzymes are utilized to cut the DNA extracted into parts or 'fragments'. These pieces are then placed in a special gel where an electric current separates the smaller and larger fragments. From there, they are transferred to a nylon membrane and a DNA probe which recognizes and adheres to the common fragments.

The fragments of both the 'presumed parents' and the child are tested by usually swabbing and collecting samples from the inside of the cheek. Blood or cultured cells may also be used. This determines if the child genetically belongs, or was made, by the parents. Typically the question of parenthood comes from a man claiming that he is not the father. When the mother is tested it is usually in cases of a murdered baby or child, abandonment, etc. The inherited DNA passed down from a mother is called mitochondrial DNA, or mtDNA.

How Does DNA Testing Work?

A child carries half of its DNA from the mother and half its DNA from the father. This means that DNA fragments will be identical to the parents. Let's say a person is fighting paternity and goes to get DNA tested. DNA is taken from the child and presumed father. An even number of fragment tests are performed because 50% of the DNA in the child should match the father's. If the even number of fragments tested is 12 then half of them (which are 6) would or should prove to be identical with the father.

As far as siblings are considered the same genetics apply, the children should match up if they had the same parents. This is true except for cases of half siblings. In that case the DNA will match at 50% because instead of full siblings containing half of both the mother and father the DNA will only be half matching with the other sibling.

Twins are a bit different. There are two kinds of twins: identical which means that an egg split which would mean that the two kids would have identical DNA. Fraternal twins are two separate eggs being fertilized by two different sperm would result in small random differences in the DNA structure.

DNA Testing Conclusion

Regardless of why DNA testing is employed, it is a valid method of learning about whom a person is and who made them. This is vitally important in so many different ways depending greatly on the circumstances. The DNA testing is so precise that it delivers a 99.9999% accuracy level.