How does DNA testing work?
DNA profiling, a fundamental breakthrough in the field of paternity testing, allows for direct examination of the genetic material that a child inherited from its biological parents. During the testing process, the genetic characteristics of a child are first compared to those of its mother. Those characteristics that cannot be found in the mother must have been inherited from the biological father. If the tested man does not contain the genetic characteristics necessary to be the biological father of the child, he is excluded. If the DNA of the tested man does contain those genetic characteristics, then this man cannot be excluded and the probability that this man is the true biological father can be calculated.
It works by detecting certain parts, or markers in the DNA molecule that are known to vary greatly between unrelated people. Our tests compare the DNA at a number of these markers to determine if people are related. The process is called Short Tandem Repeat (STR) profiling. STR profiling is a very sensitive DNA testing procedure that was originally developed for forensic analysis. DNA is extracted from the sample and a special enzyme is used to copy the genetic code at the relevant regions in the DNA. An STR profile is the result of several separate DNA tests.
The DNA test is typically a cheek swab, which collects tissue cells. The laboratory examines these cells and uses standardized protocols to count the number of repeats of genetic patterns at standardized locations on the DNA helix. A DNA result is a set of repeats (numbers) at particular addresses (markers). By comparing the numbers at the markers, we can determine if a man shares a common ancestor with a second sample. Typically, this is recorded as the number of exact matches and the total number of markers, i.e.: 12/12, 23/25 33/37, etc. Generally, for a greater number of markers, there is a higher reliability and for a closer the match in numbers, there is a closer relationship.
The DNA test is typically a cheek swab, which collects tissue cells. The laboratory examines these cells and uses standardized protocols to count the number of repeats of genetic patterns at standardized locations on the DNA helix. A DNA result is a set of repeats (numbers) at particular addresses (markers). By comparing the numbers at the markers, we can determine if a man shares a common ancestor with a second sample. Typically, this is recorded as the number of exact matches and the total number of markers, i.e.: 12/12, 23/25 33/37, etc. Generally, for a greater number of markers, there is a higher reliability and for a closer the match in numbers, there is a closer relationship.
All people have 23 pairs of chromosomes, 46 in total. One half is inherited from our mother and the other half is inherited from our father. When a DNA test is performed, the laboratory obtains the DNA profile of the child and compares it to the profile of the alleged father. If the alleged father is the true biological father of the child, then the half of the child’s DNA that came from the father will match the alleged father’s DNA profile perfectly. If the child’s DNA does not match the alleged father’s profile, then the alleged father can be conclusively excluded as being the biological father of the child. When you receive your test report, the report will either state “exclusion”, meaning that the alleged father is not the biological father of the child, or else the report will state “inclusion”, meaning that the alleged father is the true biological father of the child.
