How DNA testing works – Step by step flowchart

The Technology of DNA Kinship Testing

DNA relationship analysis is based on the Mendelian laws of inheritance. Each child has a unique DNA profile inherited equally from each parent.

Samples of DNA-containing material taken from the mother, alleged father and child are characterized. By comparing the DNA profile of the mother and child - the maternal contribution to the child can be determined. The child's DNA characteristics not found in the mother are the characteristics of the biological father.

The DNA characteristics of the biological father are then compared to the alleged father's DNA profile. If the alleged father's DNA profile does not match the profile of the biologic father, paternity of the child by the alleged father is excluded. (The biological father has not been identified.)

If the alleged father's DNA profile matches the biologic father's profile, the findings are compatible with paternity. A probability of paternity is calculated from the known frequency of the biological father's DNA profile in the random population and the probability that a mating of a man with the profile of the alleged father and mother will produce the child's DNA profile. The following example presents simplified examples of these concepts.